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pcm_oss.c

/*
 *  Digital Audio (PCM) abstract layer / OSS compatible
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#if 0
#define PLUGIN_DEBUG
#endif
#if 0
#define OSS_DEBUG
#endif

#include <sound/driver.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include <linux/moduleparam.h>
#include <linux/string.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include "pcm_plugin.h"
#include <sound/info.h>
#include <linux/soundcard.h>
#include <sound/initval.h>

#define OSS_ALSAEMULVER       _SIOR ('M', 249, int)

static int dsp_map[SNDRV_CARDS];
static int adsp_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
static int nonblock_open = 1;

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
MODULE_DESCRIPTION("PCM OSS emulation for ALSA.");
MODULE_LICENSE("GPL");
module_param_array(dsp_map, int, NULL, 0444);
MODULE_PARM_DESC(dsp_map, "PCM device number assigned to 1st OSS device.");
module_param_array(adsp_map, int, NULL, 0444);
MODULE_PARM_DESC(adsp_map, "PCM device number assigned to 2nd OSS device.");
module_param(nonblock_open, bool, 0644);
MODULE_PARM_DESC(nonblock_open, "Don't block opening busy PCM devices.");
MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_PCM);
MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_PCM1);

extern int snd_mixer_oss_ioctl_card(struct snd_card *card, unsigned int cmd, unsigned long arg);
static int snd_pcm_oss_get_rate(struct snd_pcm_oss_file *pcm_oss_file);
static int snd_pcm_oss_get_channels(struct snd_pcm_oss_file *pcm_oss_file);
static int snd_pcm_oss_get_format(struct snd_pcm_oss_file *pcm_oss_file);

static inline mm_segment_t snd_enter_user(void)
{
      mm_segment_t fs = get_fs();
      set_fs(get_ds());
      return fs;
}

static inline void snd_leave_user(mm_segment_t fs)
{
      set_fs(fs);
}

/*
 * helper functions to process hw_params
 */
static int snd_interval_refine_min(struct snd_interval *i, unsigned int min, int openmin)
{
      int changed = 0;
      if (i->min < min) {
            i->min = min;
            i->openmin = openmin;
            changed = 1;
      } else if (i->min == min && !i->openmin && openmin) {
            i->openmin = 1;
            changed = 1;
      }
      if (i->integer) {
            if (i->openmin) {
                  i->min++;
                  i->openmin = 0;
            }
      }
      if (snd_interval_checkempty(i)) {
            snd_interval_none(i);
            return -EINVAL;
      }
      return changed;
}

static int snd_interval_refine_max(struct snd_interval *i, unsigned int max, int openmax)
{
      int changed = 0;
      if (i->max > max) {
            i->max = max;
            i->openmax = openmax;
            changed = 1;
      } else if (i->max == max && !i->openmax && openmax) {
            i->openmax = 1;
            changed = 1;
      }
      if (i->integer) {
            if (i->openmax) {
                  i->max--;
                  i->openmax = 0;
            }
      }
      if (snd_interval_checkempty(i)) {
            snd_interval_none(i);
            return -EINVAL;
      }
      return changed;
}

static int snd_interval_refine_set(struct snd_interval *i, unsigned int val)
{
      struct snd_interval t;
      t.empty = 0;
      t.min = t.max = val;
      t.openmin = t.openmax = 0;
      t.integer = 1;
      return snd_interval_refine(i, &t);
}

/**
 * snd_pcm_hw_param_value_min
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @dir: pointer to the direction (-1,0,1) or NULL
 *
 * Return the minimum value for field PAR.
 */
static unsigned int
snd_pcm_hw_param_value_min(const struct snd_pcm_hw_params *params,
                     snd_pcm_hw_param_t var, int *dir)
{
      if (hw_is_mask(var)) {
            if (dir)
                  *dir = 0;
            return snd_mask_min(hw_param_mask_c(params, var));
      }
      if (hw_is_interval(var)) {
            const struct snd_interval *i = hw_param_interval_c(params, var);
            if (dir)
                  *dir = i->openmin;
            return snd_interval_min(i);
      }
      return -EINVAL;
}

/**
 * snd_pcm_hw_param_value_max
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @dir: pointer to the direction (-1,0,1) or NULL
 *
 * Return the maximum value for field PAR.
 */
static unsigned int
snd_pcm_hw_param_value_max(const struct snd_pcm_hw_params *params,
                     snd_pcm_hw_param_t var, int *dir)
{
      if (hw_is_mask(var)) {
            if (dir)
                  *dir = 0;
            return snd_mask_max(hw_param_mask_c(params, var));
      }
      if (hw_is_interval(var)) {
            const struct snd_interval *i = hw_param_interval_c(params, var);
            if (dir)
                  *dir = - (int) i->openmax;
            return snd_interval_max(i);
      }
      return -EINVAL;
}

static int _snd_pcm_hw_param_mask(struct snd_pcm_hw_params *params,
                          snd_pcm_hw_param_t var,
                          const struct snd_mask *val)
{
      int changed;
      changed = snd_mask_refine(hw_param_mask(params, var), val);
      if (changed) {
            params->cmask |= 1 << var;
            params->rmask |= 1 << var;
      }
      return changed;
}

static int snd_pcm_hw_param_mask(struct snd_pcm_substream *pcm,
                         struct snd_pcm_hw_params *params,
                         snd_pcm_hw_param_t var,
                         const struct snd_mask *val)
{
      int changed = _snd_pcm_hw_param_mask(params, var, val);
      if (changed < 0)
            return changed;
      if (params->rmask) {
            int err = snd_pcm_hw_refine(pcm, params);
            if (err < 0)
                  return err;
      }
      return 0;
}

static int _snd_pcm_hw_param_min(struct snd_pcm_hw_params *params,
                         snd_pcm_hw_param_t var, unsigned int val,
                         int dir)
{
      int changed;
      int open = 0;
      if (dir) {
            if (dir > 0) {
                  open = 1;
            } else if (dir < 0) {
                  if (val > 0) {
                        open = 1;
                        val--;
                  }
            }
      }
      if (hw_is_mask(var))
            changed = snd_mask_refine_min(hw_param_mask(params, var),
                                    val + !!open);
      else if (hw_is_interval(var))
            changed = snd_interval_refine_min(hw_param_interval(params, var),
                                      val, open);
      else
            return -EINVAL;
      if (changed) {
            params->cmask |= 1 << var;
            params->rmask |= 1 << var;
      }
      return changed;
}

/**
 * snd_pcm_hw_param_min
 * @pcm: PCM instance
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @val: minimal value
 * @dir: pointer to the direction (-1,0,1) or NULL
 *
 * Inside configuration space defined by PARAMS remove from PAR all 
 * values < VAL. Reduce configuration space accordingly.
 * Return new minimum or -EINVAL if the configuration space is empty
 */
static int snd_pcm_hw_param_min(struct snd_pcm_substream *pcm,
                        struct snd_pcm_hw_params *params,
                        snd_pcm_hw_param_t var, unsigned int val,
                        int *dir)
{
      int changed = _snd_pcm_hw_param_min(params, var, val, dir ? *dir : 0);
      if (changed < 0)
            return changed;
      if (params->rmask) {
            int err = snd_pcm_hw_refine(pcm, params);
            if (err < 0)
                  return err;
      }
      return snd_pcm_hw_param_value_min(params, var, dir);
}

static int _snd_pcm_hw_param_max(struct snd_pcm_hw_params *params,
                         snd_pcm_hw_param_t var, unsigned int val,
                         int dir)
{
      int changed;
      int open = 0;
      if (dir) {
            if (dir < 0) {
                  open = 1;
            } else if (dir > 0) {
                  open = 1;
                  val++;
            }
      }
      if (hw_is_mask(var)) {
            if (val == 0 && open) {
                  snd_mask_none(hw_param_mask(params, var));
                  changed = -EINVAL;
            } else
                  changed = snd_mask_refine_max(hw_param_mask(params, var),
                                          val - !!open);
      } else if (hw_is_interval(var))
            changed = snd_interval_refine_max(hw_param_interval(params, var),
                                      val, open);
      else
            return -EINVAL;
      if (changed) {
            params->cmask |= 1 << var;
            params->rmask |= 1 << var;
      }
      return changed;
}

/**
 * snd_pcm_hw_param_max
 * @pcm: PCM instance
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @val: maximal value
 * @dir: pointer to the direction (-1,0,1) or NULL
 *
 * Inside configuration space defined by PARAMS remove from PAR all 
 *  values >= VAL + 1. Reduce configuration space accordingly.
 *  Return new maximum or -EINVAL if the configuration space is empty
 */
static int snd_pcm_hw_param_max(struct snd_pcm_substream *pcm,
                        struct snd_pcm_hw_params *params,
                        snd_pcm_hw_param_t var, unsigned int val,
                        int *dir)
{
      int changed = _snd_pcm_hw_param_max(params, var, val, dir ? *dir : 0);
      if (changed < 0)
            return changed;
      if (params->rmask) {
            int err = snd_pcm_hw_refine(pcm, params);
            if (err < 0)
                  return err;
      }
      return snd_pcm_hw_param_value_max(params, var, dir);
}

static int boundary_sub(int a, int adir,
                  int b, int bdir,
                  int *c, int *cdir)
{
      adir = adir < 0 ? -1 : (adir > 0 ? 1 : 0);
      bdir = bdir < 0 ? -1 : (bdir > 0 ? 1 : 0);
      *c = a - b;
      *cdir = adir - bdir;
      if (*cdir == -2) {
            (*c)--;
      } else if (*cdir == 2) {
            (*c)++;
      }
      return 0;
}

static int boundary_lt(unsigned int a, int adir,
                   unsigned int b, int bdir)
{
      if (adir < 0) {
            a--;
            adir = 1;
      } else if (adir > 0)
            adir = 1;
      if (bdir < 0) {
            b--;
            bdir = 1;
      } else if (bdir > 0)
            bdir = 1;
      return a < b || (a == b && adir < bdir);
}

/* Return 1 if min is nearer to best than max */
static int boundary_nearer(int min, int mindir,
                     int best, int bestdir,
                     int max, int maxdir)
{
      int dmin, dmindir;
      int dmax, dmaxdir;
      boundary_sub(best, bestdir, min, mindir, &dmin, &dmindir);
      boundary_sub(max, maxdir, best, bestdir, &dmax, &dmaxdir);
      return boundary_lt(dmin, dmindir, dmax, dmaxdir);
}

/**
 * snd_pcm_hw_param_near
 * @pcm: PCM instance
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @best: value to set
 * @dir: pointer to the direction (-1,0,1) or NULL
 *
 * Inside configuration space defined by PARAMS set PAR to the available value
 * nearest to VAL. Reduce configuration space accordingly.
 * This function cannot be called for SNDRV_PCM_HW_PARAM_ACCESS,
 * SNDRV_PCM_HW_PARAM_FORMAT, SNDRV_PCM_HW_PARAM_SUBFORMAT.
 * Return the value found.
  */
static int snd_pcm_hw_param_near(struct snd_pcm_substream *pcm,
                         struct snd_pcm_hw_params *params,
                         snd_pcm_hw_param_t var, unsigned int best,
                         int *dir)
{
      struct snd_pcm_hw_params *save = NULL;
      int v;
      unsigned int saved_min;
      int last = 0;
      int min, max;
      int mindir, maxdir;
      int valdir = dir ? *dir : 0;
      /* FIXME */
      if (best > INT_MAX)
            best = INT_MAX;
      min = max = best;
      mindir = maxdir = valdir;
      if (maxdir > 0)
            maxdir = 0;
      else if (maxdir == 0)
            maxdir = -1;
      else {
            maxdir = 1;
            max--;
      }
      save = kmalloc(sizeof(*save), GFP_KERNEL);
      if (save == NULL)
            return -ENOMEM;
      *save = *params;
      saved_min = min;
      min = snd_pcm_hw_param_min(pcm, params, var, min, &mindir);
      if (min >= 0) {
            struct snd_pcm_hw_params *params1;
            if (max < 0)
                  goto _end;
            if ((unsigned int)min == saved_min && mindir == valdir)
                  goto _end;
            params1 = kmalloc(sizeof(*params1), GFP_KERNEL);
            if (params1 == NULL) {
                  kfree(save);
                  return -ENOMEM;
            }
            *params1 = *save;
            max = snd_pcm_hw_param_max(pcm, params1, var, max, &maxdir);
            if (max < 0) {
                  kfree(params1);
                  goto _end;
            }
            if (boundary_nearer(max, maxdir, best, valdir, min, mindir)) {
                  *params = *params1;
                  last = 1;
            }
            kfree(params1);
      } else {
            *params = *save;
            max = snd_pcm_hw_param_max(pcm, params, var, max, &maxdir);
            snd_assert(max >= 0, return -EINVAL);
            last = 1;
      }
 _end:
      kfree(save);
      if (last)
            v = snd_pcm_hw_param_last(pcm, params, var, dir);
      else
            v = snd_pcm_hw_param_first(pcm, params, var, dir);
      snd_assert(v >= 0, return -EINVAL);
      return v;
}

static int _snd_pcm_hw_param_set(struct snd_pcm_hw_params *params,
                         snd_pcm_hw_param_t var, unsigned int val,
                         int dir)
{
      int changed;
      if (hw_is_mask(var)) {
            struct snd_mask *m = hw_param_mask(params, var);
            if (val == 0 && dir < 0) {
                  changed = -EINVAL;
                  snd_mask_none(m);
            } else {
                  if (dir > 0)
                        val++;
                  else if (dir < 0)
                        val--;
                  changed = snd_mask_refine_set(hw_param_mask(params, var), val);
            }
      } else if (hw_is_interval(var)) {
            struct snd_interval *i = hw_param_interval(params, var);
            if (val == 0 && dir < 0) {
                  changed = -EINVAL;
                  snd_interval_none(i);
            } else if (dir == 0)
                  changed = snd_interval_refine_set(i, val);
            else {
                  struct snd_interval t;
                  t.openmin = 1;
                  t.openmax = 1;
                  t.empty = 0;
                  t.integer = 0;
                  if (dir < 0) {
                        t.min = val - 1;
                        t.max = val;
                  } else {
                        t.min = val;
                        t.max = val+1;
                  }
                  changed = snd_interval_refine(i, &t);
            }
      } else
            return -EINVAL;
      if (changed) {
            params->cmask |= 1 << var;
            params->rmask |= 1 << var;
      }
      return changed;
}

/**
 * snd_pcm_hw_param_set
 * @pcm: PCM instance
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @val: value to set
 * @dir: pointer to the direction (-1,0,1) or NULL
 *
 * Inside configuration space defined by PARAMS remove from PAR all 
 * values != VAL. Reduce configuration space accordingly.
 *  Return VAL or -EINVAL if the configuration space is empty
 */
static int snd_pcm_hw_param_set(struct snd_pcm_substream *pcm,
                        struct snd_pcm_hw_params *params,
                        snd_pcm_hw_param_t var, unsigned int val,
                        int dir)
{
      int changed = _snd_pcm_hw_param_set(params, var, val, dir);
      if (changed < 0)
            return changed;
      if (params->rmask) {
            int err = snd_pcm_hw_refine(pcm, params);
            if (err < 0)
                  return err;
      }
      return snd_pcm_hw_param_value(params, var, NULL);
}

static int _snd_pcm_hw_param_setinteger(struct snd_pcm_hw_params *params,
                              snd_pcm_hw_param_t var)
{
      int changed;
      changed = snd_interval_setinteger(hw_param_interval(params, var));
      if (changed) {
            params->cmask |= 1 << var;
            params->rmask |= 1 << var;
      }
      return changed;
}
      
/*
 * plugin
 */

#ifdef CONFIG_SND_PCM_OSS_PLUGINS
static int snd_pcm_oss_plugin_clear(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct snd_pcm_plugin *plugin, *next;
      
      plugin = runtime->oss.plugin_first;
      while (plugin) {
            next = plugin->next;
            snd_pcm_plugin_free(plugin);
            plugin = next;
      }
      runtime->oss.plugin_first = runtime->oss.plugin_last = NULL;
      return 0;
}

static int snd_pcm_plugin_insert(struct snd_pcm_plugin *plugin)
{
      struct snd_pcm_runtime *runtime = plugin->plug->runtime;
      plugin->next = runtime->oss.plugin_first;
      plugin->prev = NULL;
      if (runtime->oss.plugin_first) {
            runtime->oss.plugin_first->prev = plugin;
            runtime->oss.plugin_first = plugin;
      } else {
            runtime->oss.plugin_last =
            runtime->oss.plugin_first = plugin;
      }
      return 0;
}

int snd_pcm_plugin_append(struct snd_pcm_plugin *plugin)
{
      struct snd_pcm_runtime *runtime = plugin->plug->runtime;
      plugin->next = NULL;
      plugin->prev = runtime->oss.plugin_last;
      if (runtime->oss.plugin_last) {
            runtime->oss.plugin_last->next = plugin;
            runtime->oss.plugin_last = plugin;
      } else {
            runtime->oss.plugin_last =
            runtime->oss.plugin_first = plugin;
      }
      return 0;
}
#endif /* CONFIG_SND_PCM_OSS_PLUGINS */

static long snd_pcm_oss_bytes(struct snd_pcm_substream *substream, long frames)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      long buffer_size = snd_pcm_lib_buffer_bytes(substream);
      long bytes = frames_to_bytes(runtime, frames);
      if (buffer_size == runtime->oss.buffer_bytes)
            return bytes;
#if BITS_PER_LONG >= 64
      return runtime->oss.buffer_bytes * bytes / buffer_size;
#else
      {
            u64 bsize = (u64)runtime->oss.buffer_bytes * (u64)bytes;
            u32 rem;
            div64_32(&bsize, buffer_size, &rem);
            return (long)bsize;
      }
#endif
}

static long snd_pcm_alsa_frames(struct snd_pcm_substream *substream, long bytes)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      long buffer_size = snd_pcm_lib_buffer_bytes(substream);
      if (buffer_size == runtime->oss.buffer_bytes)
            return bytes_to_frames(runtime, bytes);
      return bytes_to_frames(runtime, (buffer_size * bytes) / runtime->oss.buffer_bytes);
}

/* define extended formats in the recent OSS versions (if any) */
/* linear formats */
#define AFMT_S32_LE      0x00001000
#define AFMT_S32_BE      0x00002000
#define AFMT_S24_LE      0x00008000
#define AFMT_S24_BE      0x00010000
#define AFMT_S24_PACKED  0x00040000

/* other supported formats */
#define AFMT_FLOAT       0x00004000
#define AFMT_SPDIF_RAW   0x00020000

/* unsupported formats */
#define AFMT_AC3         0x00000400
#define AFMT_VORBIS      0x00000800

static int snd_pcm_oss_format_from(int format)
{
      switch (format) {
      case AFMT_MU_LAW: return SNDRV_PCM_FORMAT_MU_LAW;
      case AFMT_A_LAW:  return SNDRV_PCM_FORMAT_A_LAW;
      case AFMT_IMA_ADPCM:    return SNDRV_PCM_FORMAT_IMA_ADPCM;
      case AFMT_U8:           return SNDRV_PCM_FORMAT_U8;
      case AFMT_S16_LE: return SNDRV_PCM_FORMAT_S16_LE;
      case AFMT_S16_BE: return SNDRV_PCM_FORMAT_S16_BE;
      case AFMT_S8:           return SNDRV_PCM_FORMAT_S8;
      case AFMT_U16_LE: return SNDRV_PCM_FORMAT_U16_LE;
      case AFMT_U16_BE: return SNDRV_PCM_FORMAT_U16_BE;
      case AFMT_MPEG:         return SNDRV_PCM_FORMAT_MPEG;
      case AFMT_S32_LE: return SNDRV_PCM_FORMAT_S32_LE;
      case AFMT_S32_BE: return SNDRV_PCM_FORMAT_S32_BE;
      case AFMT_S24_LE: return SNDRV_PCM_FORMAT_S24_LE;
      case AFMT_S24_BE: return SNDRV_PCM_FORMAT_S24_BE;
      case AFMT_S24_PACKED:   return SNDRV_PCM_FORMAT_S24_3LE;
      case AFMT_FLOAT:  return SNDRV_PCM_FORMAT_FLOAT;
      case AFMT_SPDIF_RAW:    return SNDRV_PCM_FORMAT_IEC958_SUBFRAME;
      default:          return SNDRV_PCM_FORMAT_U8;
      }
}

static int snd_pcm_oss_format_to(int format)
{
      switch (format) {
      case SNDRV_PCM_FORMAT_MU_LAW: return AFMT_MU_LAW;
      case SNDRV_PCM_FORMAT_A_LAW:  return AFMT_A_LAW;
      case SNDRV_PCM_FORMAT_IMA_ADPCM:    return AFMT_IMA_ADPCM;
      case SNDRV_PCM_FORMAT_U8:           return AFMT_U8;
      case SNDRV_PCM_FORMAT_S16_LE: return AFMT_S16_LE;
      case SNDRV_PCM_FORMAT_S16_BE: return AFMT_S16_BE;
      case SNDRV_PCM_FORMAT_S8:           return AFMT_S8;
      case SNDRV_PCM_FORMAT_U16_LE: return AFMT_U16_LE;
      case SNDRV_PCM_FORMAT_U16_BE: return AFMT_U16_BE;
      case SNDRV_PCM_FORMAT_MPEG:         return AFMT_MPEG;
      case SNDRV_PCM_FORMAT_S32_LE: return AFMT_S32_LE;
      case SNDRV_PCM_FORMAT_S32_BE: return AFMT_S32_BE;
      case SNDRV_PCM_FORMAT_S24_LE: return AFMT_S24_LE;
      case SNDRV_PCM_FORMAT_S24_BE: return AFMT_S24_BE;
      case SNDRV_PCM_FORMAT_S24_3LE:      return AFMT_S24_PACKED;
      case SNDRV_PCM_FORMAT_FLOAT:  return AFMT_FLOAT;
      case SNDRV_PCM_FORMAT_IEC958_SUBFRAME: return AFMT_SPDIF_RAW;
      default:                return -EINVAL;
      }
}

static int snd_pcm_oss_period_size(struct snd_pcm_substream *substream, 
                           struct snd_pcm_hw_params *oss_params,
                           struct snd_pcm_hw_params *slave_params)
{
      size_t s;
      size_t oss_buffer_size, oss_period_size, oss_periods;
      size_t min_period_size, max_period_size;
      struct snd_pcm_runtime *runtime = substream->runtime;
      size_t oss_frame_size;

      oss_frame_size = snd_pcm_format_physical_width(params_format(oss_params)) *
                   params_channels(oss_params) / 8;

      oss_buffer_size = snd_pcm_plug_client_size(substream,
                                       snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, NULL)) * oss_frame_size;
      oss_buffer_size = 1 << ld2(oss_buffer_size);
      if (atomic_read(&substream->mmap_count)) {
            if (oss_buffer_size > runtime->oss.mmap_bytes)
                  oss_buffer_size = runtime->oss.mmap_bytes;
      }

      if (substream->oss.setup.period_size > 16)
            oss_period_size = substream->oss.setup.period_size;
      else if (runtime->oss.fragshift) {
            oss_period_size = 1 << runtime->oss.fragshift;
            if (oss_period_size > oss_buffer_size / 2)
                  oss_period_size = oss_buffer_size / 2;
      } else {
            int sd;
            size_t bytes_per_sec = params_rate(oss_params) * snd_pcm_format_physical_width(params_format(oss_params)) * params_channels(oss_params) / 8;

            oss_period_size = oss_buffer_size;
            do {
                  oss_period_size /= 2;
            } while (oss_period_size > bytes_per_sec);
            if (runtime->oss.subdivision == 0) {
                  sd = 4;
                  if (oss_period_size / sd > 4096)
                        sd *= 2;
                  if (oss_period_size / sd < 4096)
                        sd = 1;
            } else
                  sd = runtime->oss.subdivision;
            oss_period_size /= sd;
            if (oss_period_size < 16)
                  oss_period_size = 16;
      }

      min_period_size = snd_pcm_plug_client_size(substream,
                                       snd_pcm_hw_param_value_min(slave_params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, NULL));
      min_period_size *= oss_frame_size;
      min_period_size = 1 << (ld2(min_period_size - 1) + 1);
      if (oss_period_size < min_period_size)
            oss_period_size = min_period_size;

      max_period_size = snd_pcm_plug_client_size(substream,
                                       snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, NULL));
      max_period_size *= oss_frame_size;
      max_period_size = 1 << ld2(max_period_size);
      if (oss_period_size > max_period_size)
            oss_period_size = max_period_size;

      oss_periods = oss_buffer_size / oss_period_size;

      if (substream->oss.setup.periods > 1)
            oss_periods = substream->oss.setup.periods;

      s = snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_PERIODS, NULL);
      if (runtime->oss.maxfrags && s > runtime->oss.maxfrags)
            s = runtime->oss.maxfrags;
      if (oss_periods > s)
            oss_periods = s;

      s = snd_pcm_hw_param_value_min(slave_params, SNDRV_PCM_HW_PARAM_PERIODS, NULL);
      if (s < 2)
            s = 2;
      if (oss_periods < s)
            oss_periods = s;

      while (oss_period_size * oss_periods > oss_buffer_size)
            oss_period_size /= 2;

      snd_assert(oss_period_size >= 16, return -EINVAL);
      runtime->oss.period_bytes = oss_period_size;
      runtime->oss.period_frames = 1;
      runtime->oss.periods = oss_periods;
      return 0;
}

static int choose_rate(struct snd_pcm_substream *substream,
                   struct snd_pcm_hw_params *params, unsigned int best_rate)
{
      struct snd_interval *it;
      struct snd_pcm_hw_params *save;
      unsigned int rate, prev;

      save = kmalloc(sizeof(*save), GFP_KERNEL);
      if (save == NULL)
            return -ENOMEM;
      *save = *params;
      it = hw_param_interval(save, SNDRV_PCM_HW_PARAM_RATE);

      /* try multiples of the best rate */
      rate = best_rate;
      for (;;) {
            if (it->max < rate || (it->max == rate && it->openmax))
                  break;
            if (it->min < rate || (it->min == rate && !it->openmin)) {
                  int ret;
                  ret = snd_pcm_hw_param_set(substream, params,
                                       SNDRV_PCM_HW_PARAM_RATE,
                                       rate, 0);
                  if (ret == (int)rate) {
                        kfree(save);
                        return rate;
                  }
                  *params = *save;
            }
            prev = rate;
            rate += best_rate;
            if (rate <= prev)
                  break;
      }

      /* not found, use the nearest rate */
      kfree(save);
      return snd_pcm_hw_param_near(substream, params, SNDRV_PCM_HW_PARAM_RATE, best_rate, NULL);
}

static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct snd_pcm_hw_params *params, *sparams;
      struct snd_pcm_sw_params *sw_params;
      ssize_t oss_buffer_size, oss_period_size;
      size_t oss_frame_size;
      int err;
      int direct;
      int format, sformat, n;
      struct snd_mask sformat_mask;
      struct snd_mask mask;

      if (mutex_lock_interruptible(&runtime->oss.params_lock))
            return -EINTR;
      sw_params = kmalloc(sizeof(*sw_params), GFP_KERNEL);
      params = kmalloc(sizeof(*params), GFP_KERNEL);
      sparams = kmalloc(sizeof(*sparams), GFP_KERNEL);
      if (!sw_params || !params || !sparams) {
            snd_printd("No memory\n");
            err = -ENOMEM;
            goto failure;
      }

      if (atomic_read(&substream->mmap_count))
            direct = 1;
      else
            direct = substream->oss.setup.direct;

      _snd_pcm_hw_params_any(sparams);
      _snd_pcm_hw_param_setinteger(sparams, SNDRV_PCM_HW_PARAM_PERIODS);
      _snd_pcm_hw_param_min(sparams, SNDRV_PCM_HW_PARAM_PERIODS, 2, 0);
      snd_mask_none(&mask);
      if (atomic_read(&substream->mmap_count))
            snd_mask_set(&mask, SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
      else {
            snd_mask_set(&mask, SNDRV_PCM_ACCESS_RW_INTERLEAVED);
            if (!direct)
                  snd_mask_set(&mask, SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
      }
      err = snd_pcm_hw_param_mask(substream, sparams, SNDRV_PCM_HW_PARAM_ACCESS, &mask);
      if (err < 0) {
            snd_printd("No usable accesses\n");
            err = -EINVAL;
            goto failure;
      }
      choose_rate(substream, sparams, runtime->oss.rate);
      snd_pcm_hw_param_near(substream, sparams, SNDRV_PCM_HW_PARAM_CHANNELS, runtime->oss.channels, NULL);

      format = snd_pcm_oss_format_from(runtime->oss.format);

      sformat_mask = *hw_param_mask(sparams, SNDRV_PCM_HW_PARAM_FORMAT);
      if (direct)
            sformat = format;
      else
            sformat = snd_pcm_plug_slave_format(format, &sformat_mask);

      if (sformat < 0 || !snd_mask_test(&sformat_mask, sformat)) {
            for (sformat = 0; sformat <= SNDRV_PCM_FORMAT_LAST; sformat++) {
                  if (snd_mask_test(&sformat_mask, sformat) &&
                      snd_pcm_oss_format_to(sformat) >= 0)
                        break;
            }
            if (sformat > SNDRV_PCM_FORMAT_LAST) {
                  snd_printd("Cannot find a format!!!\n");
                  err = -EINVAL;
                  goto failure;
            }
      }
      err = _snd_pcm_hw_param_set(sparams, SNDRV_PCM_HW_PARAM_FORMAT, sformat, 0);
      snd_assert(err >= 0, goto failure);

      if (direct) {
            memcpy(params, sparams, sizeof(*params));
      } else {
            _snd_pcm_hw_params_any(params);
            _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_ACCESS,
                              SNDRV_PCM_ACCESS_RW_INTERLEAVED, 0);
            _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_FORMAT,
                              snd_pcm_oss_format_from(runtime->oss.format), 0);
            _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_CHANNELS,
                              runtime->oss.channels, 0);
            _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_RATE,
                              runtime->oss.rate, 0);
            pdprintf("client: access = %i, format = %i, channels = %i, rate = %i\n",
                   params_access(params), params_format(params),
                   params_channels(params), params_rate(params));
      }
      pdprintf("slave: access = %i, format = %i, channels = %i, rate = %i\n",
             params_access(sparams), params_format(sparams),
             params_channels(sparams), params_rate(sparams));

      oss_frame_size = snd_pcm_format_physical_width(params_format(params)) *
                   params_channels(params) / 8;

#ifdef CONFIG_SND_PCM_OSS_PLUGINS
      snd_pcm_oss_plugin_clear(substream);
      if (!direct) {
            /* add necessary plugins */
            snd_pcm_oss_plugin_clear(substream);
            if ((err = snd_pcm_plug_format_plugins(substream,
                                           params, 
                                           sparams)) < 0) {
                  snd_printd("snd_pcm_plug_format_plugins failed: %i\n", err);
                  snd_pcm_oss_plugin_clear(substream);
                  goto failure;
            }
            if (runtime->oss.plugin_first) {
                  struct snd_pcm_plugin *plugin;
                  if ((err = snd_pcm_plugin_build_io(substream, sparams, &plugin)) < 0) {
                        snd_printd("snd_pcm_plugin_build_io failed: %i\n", err);
                        snd_pcm_oss_plugin_clear(substream);
                        goto failure;
                  }
                  if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                        err = snd_pcm_plugin_append(plugin);
                  } else {
                        err = snd_pcm_plugin_insert(plugin);
                  }
                  if (err < 0) {
                        snd_pcm_oss_plugin_clear(substream);
                        goto failure;
                  }
            }
      }
#endif

      err = snd_pcm_oss_period_size(substream, params, sparams);
      if (err < 0)
            goto failure;

      n = snd_pcm_plug_slave_size(substream, runtime->oss.period_bytes / oss_frame_size);
      err = snd_pcm_hw_param_near(substream, sparams, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, n, NULL);
      snd_assert(err >= 0, goto failure);

      err = snd_pcm_hw_param_near(substream, sparams, SNDRV_PCM_HW_PARAM_PERIODS,
                             runtime->oss.periods, NULL);
      snd_assert(err >= 0, goto failure);

      snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);

      if ((err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_HW_PARAMS, sparams)) < 0) {
            snd_printd("HW_PARAMS failed: %i\n", err);
            goto failure;
      }

      memset(sw_params, 0, sizeof(*sw_params));
      if (runtime->oss.trigger) {
            sw_params->start_threshold = 1;
      } else {
            sw_params->start_threshold = runtime->boundary;
      }
      if (atomic_read(&substream->mmap_count) ||
          substream->stream == SNDRV_PCM_STREAM_CAPTURE)
            sw_params->stop_threshold = runtime->boundary;
      else
            sw_params->stop_threshold = runtime->buffer_size;
      sw_params->tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
      sw_params->period_step = 1;
      sw_params->sleep_min = 0;
      sw_params->avail_min = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
            1 : runtime->period_size;
      sw_params->xfer_align = 1;
      if (atomic_read(&substream->mmap_count) ||
          substream->oss.setup.nosilence) {
            sw_params->silence_threshold = 0;
            sw_params->silence_size = 0;
      } else {
            snd_pcm_uframes_t frames;
            frames = runtime->period_size + 16;
            if (frames > runtime->buffer_size)
                  frames = runtime->buffer_size;
            sw_params->silence_threshold = frames;
            sw_params->silence_size = frames;
      }

      if ((err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_SW_PARAMS, sw_params)) < 0) {
            snd_printd("SW_PARAMS failed: %i\n", err);
            goto failure;
      }

      runtime->oss.periods = params_periods(sparams);
      oss_period_size = snd_pcm_plug_client_size(substream, params_period_size(sparams));
      snd_assert(oss_period_size >= 0, err = -EINVAL; goto failure);
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
      if (runtime->oss.plugin_first) {
            err = snd_pcm_plug_alloc(substream, oss_period_size);
            if (err < 0)
                  goto failure;
      }
#endif
      oss_period_size *= oss_frame_size;

      oss_buffer_size = oss_period_size * runtime->oss.periods;
      snd_assert(oss_buffer_size >= 0, err = -EINVAL; goto failure);

      runtime->oss.period_bytes = oss_period_size;
      runtime->oss.buffer_bytes = oss_buffer_size;

      pdprintf("oss: period bytes = %i, buffer bytes = %i\n",
             runtime->oss.period_bytes,
             runtime->oss.buffer_bytes);
      pdprintf("slave: period_size = %i, buffer_size = %i\n",
             params_period_size(sparams),
             params_buffer_size(sparams));

      runtime->oss.format = snd_pcm_oss_format_to(params_format(params));
      runtime->oss.channels = params_channels(params);
      runtime->oss.rate = params_rate(params);

      runtime->oss.params = 0;
      runtime->oss.prepare = 1;
      vfree(runtime->oss.buffer);
      runtime->oss.buffer = vmalloc(runtime->oss.period_bytes);
      runtime->oss.buffer_used = 0;
      if (runtime->dma_area)
            snd_pcm_format_set_silence(runtime->format, runtime->dma_area, bytes_to_samples(runtime, runtime->dma_bytes));

      runtime->oss.period_frames = snd_pcm_alsa_frames(substream, oss_period_size);

      err = 0;
failure:
      kfree(sw_params);
      kfree(params);
      kfree(sparams);
      mutex_unlock(&runtime->oss.params_lock);
      return err;
}

static int snd_pcm_oss_get_active_substream(struct snd_pcm_oss_file *pcm_oss_file, struct snd_pcm_substream **r_substream)
{
      int idx, err;
      struct snd_pcm_substream *asubstream = NULL, *substream;

      for (idx = 0; idx < 2; idx++) {
            substream = pcm_oss_file->streams[idx];
            if (substream == NULL)
                  continue;
            if (asubstream == NULL)
                  asubstream = substream;
            if (substream->runtime->oss.params) {
                  err = snd_pcm_oss_change_params(substream);
                  if (err < 0)
                        return err;
            }
      }
      snd_assert(asubstream != NULL, return -EIO);
      if (r_substream)
            *r_substream = asubstream;
      return 0;
}

static int snd_pcm_oss_prepare(struct snd_pcm_substream *substream)
{
      int err;
      struct snd_pcm_runtime *runtime = substream->runtime;

      err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL);
      if (err < 0) {
            snd_printd("snd_pcm_oss_prepare: SNDRV_PCM_IOCTL_PREPARE failed\n");
            return err;
      }
      runtime->oss.prepare = 0;
      runtime->oss.prev_hw_ptr_interrupt = 0;
      runtime->oss.period_ptr = 0;
      runtime->oss.buffer_used = 0;

      return 0;
}

static int snd_pcm_oss_make_ready(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime;
      int err;

      if (substream == NULL)
            return 0;
      runtime = substream->runtime;
      if (runtime->oss.params) {
            err = snd_pcm_oss_change_params(substream);
            if (err < 0)
                  return err;
      }
      if (runtime->oss.prepare) {
            err = snd_pcm_oss_prepare(substream);
            if (err < 0)
                  return err;
      }
      return 0;
}

static int snd_pcm_oss_capture_position_fixup(struct snd_pcm_substream *substream, snd_pcm_sframes_t *delay)
{
      struct snd_pcm_runtime *runtime;
      snd_pcm_uframes_t frames;
      int err = 0;

      while (1) {
            err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, delay);
            if (err < 0)
                  break;
            runtime = substream->runtime;
            if (*delay <= (snd_pcm_sframes_t)runtime->buffer_size)
                  break;
            /* in case of overrun, skip whole periods like OSS/Linux driver does */
            /* until avail(delay) <= buffer_size */
            frames = (*delay - runtime->buffer_size) + runtime->period_size - 1;
            frames /= runtime->period_size;
            frames *= runtime->period_size;
            err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_FORWARD, &frames);
            if (err < 0)
                  break;
      }
      return err;
}

snd_pcm_sframes_t snd_pcm_oss_write3(struct snd_pcm_substream *substream, const char *ptr, snd_pcm_uframes_t frames, int in_kernel)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      int ret;
      while (1) {
            if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
                runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
#ifdef OSS_DEBUG
                  if (runtime->status->state == SNDRV_PCM_STATE_XRUN)
                        printk("pcm_oss: write: recovering from XRUN\n");
                  else
                        printk("pcm_oss: write: recovering from SUSPEND\n");
#endif
                  ret = snd_pcm_oss_prepare(substream);
                  if (ret < 0)
                        break;
            }
            if (in_kernel) {
                  mm_segment_t fs;
                  fs = snd_enter_user();
                  ret = snd_pcm_lib_write(substream, (void __user *)ptr, frames);
                  snd_leave_user(fs);
            } else {
                  ret = snd_pcm_lib_write(substream, (void __user *)ptr, frames);
            }
            if (ret != -EPIPE && ret != -ESTRPIPE)
                  break;
            /* test, if we can't store new data, because the stream */
            /* has not been started */
            if (runtime->status->state == SNDRV_PCM_STATE_PREPARED)
                  return -EAGAIN;
      }
      return ret;
}

snd_pcm_sframes_t snd_pcm_oss_read3(struct snd_pcm_substream *substream, char *ptr, snd_pcm_uframes_t frames, int in_kernel)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      snd_pcm_sframes_t delay;
      int ret;
      while (1) {
            if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
                runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
#ifdef OSS_DEBUG
                  if (runtime->status->state == SNDRV_PCM_STATE_XRUN)
                        printk("pcm_oss: read: recovering from XRUN\n");
                  else
                        printk("pcm_oss: read: recovering from SUSPEND\n");
#endif
                  ret = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
                  if (ret < 0)
                        break;
            } else if (runtime->status->state == SNDRV_PCM_STATE_SETUP) {
                  ret = snd_pcm_oss_prepare(substream);
                  if (ret < 0)
                        break;
            }
            ret = snd_pcm_oss_capture_position_fixup(substream, &delay);
            if (ret < 0)
                  break;
            if (in_kernel) {
                  mm_segment_t fs;
                  fs = snd_enter_user();
                  ret = snd_pcm_lib_read(substream, (void __user *)ptr, frames);
                  snd_leave_user(fs);
            } else {
                  ret = snd_pcm_lib_read(substream, (void __user *)ptr, frames);
            }
            if (ret == -EPIPE) {
                  if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
                        ret = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
                        if (ret < 0)
                              break;
                  }
                  continue;
            }
            if (ret != -ESTRPIPE)
                  break;
      }
      return ret;
}

snd_pcm_sframes_t snd_pcm_oss_writev3(struct snd_pcm_substream *substream, void **bufs, snd_pcm_uframes_t frames, int in_kernel)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      int ret;
      while (1) {
            if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
                runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
#ifdef OSS_DEBUG
                  if (runtime->status->state == SNDRV_PCM_STATE_XRUN)
                        printk("pcm_oss: writev: recovering from XRUN\n");
                  else
                        printk("pcm_oss: writev: recovering from SUSPEND\n");
#endif
                  ret = snd_pcm_oss_prepare(substream);
                  if (ret < 0)
                        break;
            }
            if (in_kernel) {
                  mm_segment_t fs;
                  fs = snd_enter_user();
                  ret = snd_pcm_lib_writev(substream, (void __user **)bufs, frames);
                  snd_leave_user(fs);
            } else {
                  ret = snd_pcm_lib_writev(substream, (void __user **)bufs, frames);
            }
            if (ret != -EPIPE && ret != -ESTRPIPE)
                  break;

            /* test, if we can't store new data, because the stream */
            /* has not been started */
            if (runtime->status->state == SNDRV_PCM_STATE_PREPARED)
                  return -EAGAIN;
      }
      return ret;
}
      
snd_pcm_sframes_t snd_pcm_oss_readv3(struct snd_pcm_substream *substream, void **bufs, snd_pcm_uframes_t frames, int in_kernel)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      int ret;
      while (1) {
            if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
                runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
#ifdef OSS_DEBUG
                  if (runtime->status->state == SNDRV_PCM_STATE_XRUN)
                        printk("pcm_oss: readv: recovering from XRUN\n");
                  else
                        printk("pcm_oss: readv: recovering from SUSPEND\n");
#endif
                  ret = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
                  if (ret < 0)
                        break;
            } else if (runtime->status->state == SNDRV_PCM_STATE_SETUP) {
                  ret = snd_pcm_oss_prepare(substream);
                  if (ret < 0)
                        break;
            }
            if (in_kernel) {
                  mm_segment_t fs;
                  fs = snd_enter_user();
                  ret = snd_pcm_lib_readv(substream, (void __user **)bufs, frames);
                  snd_leave_user(fs);
            } else {
                  ret = snd_pcm_lib_readv(substream, (void __user **)bufs, frames);
            }
            if (ret != -EPIPE && ret != -ESTRPIPE)
                  break;
      }
      return ret;
}

static ssize_t snd_pcm_oss_write2(struct snd_pcm_substream *substream, const char *buf, size_t bytes, int in_kernel)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      snd_pcm_sframes_t frames, frames1;
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
      if (runtime->oss.plugin_first) {
            struct snd_pcm_plugin_channel *channels;
            size_t oss_frame_bytes = (runtime->oss.plugin_first->src_width * runtime->oss.plugin_first->src_format.channels) / 8;
            if (!in_kernel) {
                  if (copy_from_user(runtime->oss.buffer, (const char __user *)buf, bytes))
                        return -EFAULT;
                  buf = runtime->oss.buffer;
            }
            frames = bytes / oss_frame_bytes;
            frames1 = snd_pcm_plug_client_channels_buf(substream, (char *)buf, frames, &channels);
            if (frames1 < 0)
                  return frames1;
            frames1 = snd_pcm_plug_write_transfer(substream, channels, frames1);
            if (frames1 <= 0)
                  return frames1;
            bytes = frames1 * oss_frame_bytes;
      } else
#endif
      {
            frames = bytes_to_frames(runtime, bytes);
            frames1 = snd_pcm_oss_write3(substream, buf, frames, in_kernel);
            if (frames1 <= 0)
                  return frames1;
            bytes = frames_to_bytes(runtime, frames1);
      }
      return bytes;
}

static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const char __user *buf, size_t bytes)
{
      size_t xfer = 0;
      ssize_t tmp;
      struct snd_pcm_runtime *runtime = substream->runtime;

      if (atomic_read(&substream->mmap_count))
            return -ENXIO;

      if ((tmp = snd_pcm_oss_make_ready(substream)) < 0)
            return tmp;
      mutex_lock(&runtime->oss.params_lock);
      while (bytes > 0) {
            if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
                  tmp = bytes;
                  if (tmp + runtime->oss.buffer_used > runtime->oss.period_bytes)
                        tmp = runtime->oss.period_bytes - runtime->oss.buffer_used;
                  if (tmp > 0) {
                        if (copy_from_user(runtime->oss.buffer + runtime->oss.buffer_used, buf, tmp)) {
                              tmp = -EFAULT;
                              goto err;
                        }
                  }
                  runtime->oss.buffer_used += tmp;
                  buf += tmp;
                  bytes -= tmp;
                  xfer += tmp;
                  if (substream->oss.setup.partialfrag ||
                      runtime->oss.buffer_used == runtime->oss.period_bytes) {
                        tmp = snd_pcm_oss_write2(substream, runtime->oss.buffer + runtime->oss.period_ptr, 
                                           runtime->oss.buffer_used - runtime->oss.period_ptr, 1);
                        if (tmp <= 0)
                              goto err;
                        runtime->oss.bytes += tmp;
                        runtime->oss.period_ptr += tmp;
                        runtime->oss.period_ptr %= runtime->oss.period_bytes;
                        if (runtime->oss.period_ptr == 0 ||
                            runtime->oss.period_ptr == runtime->oss.buffer_used)
                              runtime->oss.buffer_used = 0;
                        else if ((substream->f_flags & O_NONBLOCK) != 0) {
                              tmp = -EAGAIN;
                              goto err;
                        }
                  }
            } else {
                  tmp = snd_pcm_oss_write2(substream,
                                     (const char __force *)buf,
                                     runtime->oss.period_bytes, 0);
                  if (tmp <= 0)
                        goto err;
                  runtime->oss.bytes += tmp;
                  buf += tmp;
                  bytes -= tmp;
                  xfer += tmp;
                  if ((substream->f_flags & O_NONBLOCK) != 0 &&
                      tmp != runtime->oss.period_bytes)
                        break;
            }
      }
      mutex_unlock(&runtime->oss.params_lock);
      return xfer;

 err:
      mutex_unlock(&runtime->oss.params_lock);
      return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
}

static ssize_t snd_pcm_oss_read2(struct snd_pcm_substream *substream, char *buf, size_t bytes, int in_kernel)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      snd_pcm_sframes_t frames, frames1;
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
      char __user *final_dst = (char __user *)buf;
      if (runtime->oss.plugin_first) {
            struct snd_pcm_plugin_channel *channels;
            size_t oss_frame_bytes = (runtime->oss.plugin_last->dst_width * runtime->oss.plugin_last->dst_format.channels) / 8;
            if (!in_kernel)
                  buf = runtime->oss.buffer;
            frames = bytes / oss_frame_bytes;
            frames1 = snd_pcm_plug_client_channels_buf(substream, buf, frames, &channels);
            if (frames1 < 0)
                  return frames1;
            frames1 = snd_pcm_plug_read_transfer(substream, channels, frames1);
            if (frames1 <= 0)
                  return frames1;
            bytes = frames1 * oss_frame_bytes;
            if (!in_kernel && copy_to_user(final_dst, buf, bytes))
                  return -EFAULT;
      } else
#endif
      {
            frames = bytes_to_frames(runtime, bytes);
            frames1 = snd_pcm_oss_read3(substream, buf, frames, in_kernel);
            if (frames1 <= 0)
                  return frames1;
            bytes = frames_to_bytes(runtime, frames1);
      }
      return bytes;
}

static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __user *buf, size_t bytes)
{
      size_t xfer = 0;
      ssize_t tmp;
      struct snd_pcm_runtime *runtime = substream->runtime;

      if (atomic_read(&substream->mmap_count))
            return -ENXIO;

      if ((tmp = snd_pcm_oss_make_ready(substream)) < 0)
            return tmp;
      mutex_lock(&runtime->oss.params_lock);
      while (bytes > 0) {
            if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
                  if (runtime->oss.buffer_used == 0) {
                        tmp = snd_pcm_oss_read2(substream, runtime->oss.buffer, runtime->oss.period_bytes, 1);
                        if (tmp <= 0)
                              goto err;
                        runtime->oss.bytes += tmp;
                        runtime->oss.period_ptr = tmp;
                        runtime->oss.buffer_used = tmp;
                  }
                  tmp = bytes;
                  if ((size_t) tmp > runtime->oss.buffer_used)
                        tmp = runtime->oss.buffer_used;
                  if (copy_to_user(buf, runtime->oss.buffer + (runtime->oss.period_ptr - runtime->oss.buffer_used), tmp)) {
                        tmp = -EFAULT;
                        goto err;
                  }
                  buf += tmp;
                  bytes -= tmp;
                  xfer += tmp;
                  runtime->oss.buffer_used -= tmp;
            } else {
                  tmp = snd_pcm_oss_read2(substream, (char __force *)buf,
                                    runtime->oss.period_bytes, 0);
                  if (tmp <= 0)
                        goto err;
                  runtime->oss.bytes += tmp;
                  buf += tmp;
                  bytes -= tmp;
                  xfer += tmp;
            }
      }
      mutex_unlock(&runtime->oss.params_lock);
      return xfer;

 err:
      mutex_unlock(&runtime->oss.params_lock);
      return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
}

static int snd_pcm_oss_reset(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;

      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      if (substream != NULL) {
            snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
            substream->runtime->oss.prepare = 1;
      }
      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
      if (substream != NULL) {
            snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
            substream->runtime->oss.prepare = 1;
      }
      return 0;
}

static int snd_pcm_oss_post(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      int err;

      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      if (substream != NULL) {
            if ((err = snd_pcm_oss_make_ready(substream)) < 0)
                  return err;
            snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_START, NULL);
      }
      /* note: all errors from the start action are ignored */
      /* OSS apps do not know, how to handle them */
      return 0;
}

static int snd_pcm_oss_sync1(struct snd_pcm_substream *substream, size_t size)
{
      struct snd_pcm_runtime *runtime;
      ssize_t result = 0;
      long res;
      wait_queue_t wait;

      runtime = substream->runtime;
      init_waitqueue_entry(&wait, current);
      add_wait_queue(&runtime->sleep, &wait);
#ifdef OSS_DEBUG
      printk("sync1: size = %li\n", size);
#endif
      while (1) {
            result = snd_pcm_oss_write2(substream, runtime->oss.buffer, size, 1);
            if (result > 0) {
                  runtime->oss.buffer_used = 0;
                  result = 0;
                  break;
            }
            if (result != 0 && result != -EAGAIN)
                  break;
            result = 0;
            set_current_state(TASK_INTERRUPTIBLE);
            snd_pcm_stream_lock_irq(substream);
            res = runtime->status->state;
            snd_pcm_stream_unlock_irq(substream);
            if (res != SNDRV_PCM_STATE_RUNNING) {
                  set_current_state(TASK_RUNNING);
                  break;
            }
            res = schedule_timeout(10 * HZ);
            if (signal_pending(current)) {
                  result = -ERESTARTSYS;
                  break;
            }
            if (res == 0) {
                  snd_printk(KERN_ERR "OSS sync error - DMA timeout\n");
                  result = -EIO;
                  break;
            }
      }
      remove_wait_queue(&runtime->sleep, &wait);
      return result;
}

static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
{
      int err = 0;
      unsigned int saved_f_flags;
      struct snd_pcm_substream *substream;
      struct snd_pcm_runtime *runtime;
      snd_pcm_format_t format;
      unsigned long width;
      size_t size;

      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      if (substream != NULL) {
            runtime = substream->runtime;
            if (atomic_read(&substream->mmap_count))
                  goto __direct;
            if ((err = snd_pcm_oss_make_ready(substream)) < 0)
                  return err;
            format = snd_pcm_oss_format_from(runtime->oss.format);
            width = snd_pcm_format_physical_width(format);
            mutex_lock(&runtime->oss.params_lock);
            if (runtime->oss.buffer_used > 0) {
#ifdef OSS_DEBUG
                  printk("sync: buffer_used\n");
#endif
                  size = (8 * (runtime->oss.period_bytes - runtime->oss.buffer_used) + 7) / width;
                  snd_pcm_format_set_silence(format,
                                       runtime->oss.buffer + runtime->oss.buffer_used,
                                       size);
                  err = snd_pcm_oss_sync1(substream, runtime->oss.period_bytes);
                  if (err < 0) {
                        mutex_unlock(&runtime->oss.params_lock);
                        return err;
                  }
            } else if (runtime->oss.period_ptr > 0) {
#ifdef OSS_DEBUG
                  printk("sync: period_ptr\n");
#endif
                  size = runtime->oss.period_bytes - runtime->oss.period_ptr;
                  snd_pcm_format_set_silence(format,
                                       runtime->oss.buffer,
                                       size * 8 / width);
                  err = snd_pcm_oss_sync1(substream, size);
                  if (err < 0) {
                        mutex_unlock(&runtime->oss.params_lock);
                        return err;
                  }
            }
            /*
             * The ALSA's period might be a bit large than OSS one.
             * Fill the remain portion of ALSA period with zeros.
             */
            size = runtime->control->appl_ptr % runtime->period_size;
            if (size > 0) {
                  size = runtime->period_size - size;
                  if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
                        size = (runtime->frame_bits * size) / 8;
                        while (size > 0) {
                              mm_segment_t fs;
                              size_t size1 = size < runtime->oss.period_bytes ? size : runtime->oss.period_bytes;
                              size -= size1;
                              size1 *= 8;
                              size1 /= runtime->sample_bits;
                              snd_pcm_format_set_silence(runtime->format,
                                                   runtime->oss.buffer,
                                                   size1);
                              fs = snd_enter_user();
                              snd_pcm_lib_write(substream, (void __user *)runtime->oss.buffer, size1);
                              snd_leave_user(fs);
                        }
                  } else if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
                        void __user *buffers[runtime->channels];
                        memset(buffers, 0, runtime->channels * sizeof(void *));
                        snd_pcm_lib_writev(substream, buffers, size);
                  }
            }
            mutex_unlock(&runtime->oss.params_lock);
            /*
             * finish sync: drain the buffer
             */
            __direct:
            saved_f_flags = substream->f_flags;
            substream->f_flags &= ~O_NONBLOCK;
            err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
            substream->f_flags = saved_f_flags;
            if (err < 0)
                  return err;
            runtime->oss.prepare = 1;
      }

      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
      if (substream != NULL) {
            if ((err = snd_pcm_oss_make_ready(substream)) < 0)
                  return err;
            runtime = substream->runtime;
            err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
            if (err < 0)
                  return err;
            runtime->oss.buffer_used = 0;
            runtime->oss.prepare = 1;
      }
      return 0;
}

static int snd_pcm_oss_set_rate(struct snd_pcm_oss_file *pcm_oss_file, int rate)
{
      int idx;

      for (idx = 1; idx >= 0; --idx) {
            struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
            struct snd_pcm_runtime *runtime;
            if (substream == NULL)
                  continue;
            runtime = substream->runtime;
            if (rate < 1000)
                  rate = 1000;
            else if (rate > 192000)
                  rate = 192000;
            if (runtime->oss.rate != rate) {
                  runtime->oss.params = 1;
                  runtime->oss.rate = rate;
            }
      }
      return snd_pcm_oss_get_rate(pcm_oss_file);
}

static int snd_pcm_oss_get_rate(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      int err;
      
      if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
            return err;
      return substream->runtime->oss.rate;
}

static int snd_pcm_oss_set_channels(struct snd_pcm_oss_file *pcm_oss_file, unsigned int channels)
{
      int idx;
      if (channels < 1)
            channels = 1;
      if (channels > 128)
            return -EINVAL;
      for (idx = 1; idx >= 0; --idx) {
            struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
            struct snd_pcm_runtime *runtime;
            if (substream == NULL)
                  continue;
            runtime = substream->runtime;
            if (runtime->oss.channels != channels) {
                  runtime->oss.params = 1;
                  runtime->oss.channels = channels;
            }
      }
      return snd_pcm_oss_get_channels(pcm_oss_file);
}

static int snd_pcm_oss_get_channels(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      int err;
      
      if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
            return err;
      return substream->runtime->oss.channels;
}

static int snd_pcm_oss_get_block_size(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      int err;
      
      if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
            return err;
      return substream->runtime->oss.period_bytes;
}

static int snd_pcm_oss_get_formats(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      int err;
      int direct;
      struct snd_pcm_hw_params *params;
      unsigned int formats = 0;
      struct snd_mask format_mask;
      int fmt;

      if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
            return err;
      if (atomic_read(&substream->mmap_count))
            direct = 1;
      else
            direct = substream->oss.setup.direct;
      if (!direct)
            return AFMT_MU_LAW | AFMT_U8 |
                   AFMT_S16_LE | AFMT_S16_BE |
                   AFMT_S8 | AFMT_U16_LE |
                   AFMT_U16_BE |
                  AFMT_S32_LE | AFMT_S32_BE |
                  AFMT_S24_LE | AFMT_S24_LE |
                  AFMT_S24_PACKED;
      params = kmalloc(sizeof(*params), GFP_KERNEL);
      if (!params)
            return -ENOMEM;
      _snd_pcm_hw_params_any(params);
      err = snd_pcm_hw_refine(substream, params);
      format_mask = *hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT); 
      kfree(params);
      snd_assert(err >= 0, return err);
      for (fmt = 0; fmt < 32; ++fmt) {
            if (snd_mask_test(&format_mask, fmt)) {
                  int f = snd_pcm_oss_format_to(fmt);
                  if (f >= 0)
                        formats |= f;
            }
      }
      return formats;
}

static int snd_pcm_oss_set_format(struct snd_pcm_oss_file *pcm_oss_file, int format)
{
      int formats, idx;
      
      if (format != AFMT_QUERY) {
            formats = snd_pcm_oss_get_formats(pcm_oss_file);
            if (formats < 0)
                  return formats;
            if (!(formats & format))
                  format = AFMT_U8;
            for (idx = 1; idx >= 0; --idx) {
                  struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
                  struct snd_pcm_runtime *runtime;
                  if (substream == NULL)
                        continue;
                  runtime = substream->runtime;
                  if (runtime->oss.format != format) {
                        runtime->oss.params = 1;
                        runtime->oss.format = format;
                  }
            }
      }
      return snd_pcm_oss_get_format(pcm_oss_file);
}

static int snd_pcm_oss_get_format(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      int err;
      
      if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
            return err;
      return substream->runtime->oss.format;
}

static int snd_pcm_oss_set_subdivide1(struct snd_pcm_substream *substream, int subdivide)
{
      struct snd_pcm_runtime *runtime;

      if (substream == NULL)
            return 0;
      runtime = substream->runtime;
      if (subdivide == 0) {
            subdivide = runtime->oss.subdivision;
            if (subdivide == 0)
                  subdivide = 1;
            return subdivide;
      }
      if (runtime->oss.subdivision || runtime->oss.fragshift)
            return -EINVAL;
      if (subdivide != 1 && subdivide != 2 && subdivide != 4 &&
          subdivide != 8 && subdivide != 16)
            return -EINVAL;
      runtime->oss.subdivision = subdivide;
      runtime->oss.params = 1;
      return subdivide;
}

static int snd_pcm_oss_set_subdivide(struct snd_pcm_oss_file *pcm_oss_file, int subdivide)
{
      int err = -EINVAL, idx;

      for (idx = 1; idx >= 0; --idx) {
            struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
            if (substream == NULL)
                  continue;
            if ((err = snd_pcm_oss_set_subdivide1(substream, subdivide)) < 0)
                  return err;
      }
      return err;
}

static int snd_pcm_oss_set_fragment1(struct snd_pcm_substream *substream, unsigned int val)
{
      struct snd_pcm_runtime *runtime;

      if (substream == NULL)
            return 0;
      runtime = substream->runtime;
      if (runtime->oss.subdivision || runtime->oss.fragshift)
            return -EINVAL;
      runtime->oss.fragshift = val & 0xffff;
      runtime->oss.maxfrags = (val >> 16) & 0xffff;
      if (runtime->oss.fragshift < 4)           /* < 16 */
            runtime->oss.fragshift = 4;
      if (runtime->oss.maxfrags < 2)
            runtime->oss.maxfrags = 2;
      runtime->oss.params = 1;
      return 0;
}

static int snd_pcm_oss_set_fragment(struct snd_pcm_oss_file *pcm_oss_file, unsigned int val)
{
      int err = -EINVAL, idx;

      for (idx = 1; idx >= 0; --idx) {
            struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
            if (substream == NULL)
                  continue;
            if ((err = snd_pcm_oss_set_fragment1(substream, val)) < 0)
                  return err;
      }
      return err;
}

static int snd_pcm_oss_nonblock(struct file * file)
{
      file->f_flags |= O_NONBLOCK;
      return 0;
}

static int snd_pcm_oss_get_caps1(struct snd_pcm_substream *substream, int res)
{

      if (substream == NULL) {
            res &= ~DSP_CAP_DUPLEX;
            return res;
      }
#ifdef DSP_CAP_MULTI
      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            if (substream->pstr->substream_count > 1)
                  res |= DSP_CAP_MULTI;
#endif
      /* DSP_CAP_REALTIME is set all times: */
      /* all ALSA drivers can return actual pointer in ring buffer */
#if defined(DSP_CAP_REALTIME) && 0
      {
            struct snd_pcm_runtime *runtime = substream->runtime;
            if (runtime->info & (SNDRV_PCM_INFO_BLOCK_TRANSFER|SNDRV_PCM_INFO_BATCH))
                  res &= ~DSP_CAP_REALTIME;
      }
#endif
      return res;
}

static int snd_pcm_oss_get_caps(struct snd_pcm_oss_file *pcm_oss_file)
{
      int result, idx;
      
      result = DSP_CAP_TRIGGER | DSP_CAP_MMAP   | DSP_CAP_DUPLEX | DSP_CAP_REALTIME;
      for (idx = 0; idx < 2; idx++) {
            struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
            result = snd_pcm_oss_get_caps1(substream, result);
      }
      result |= 0x0001; /* revision - same as SB AWE 64 */
      return result;
}

static void snd_pcm_oss_simulate_fill(struct snd_pcm_substream *substream, snd_pcm_uframes_t hw_ptr)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      snd_pcm_uframes_t appl_ptr;
      appl_ptr = hw_ptr + runtime->buffer_size;
      appl_ptr %= runtime->boundary;
      runtime->control->appl_ptr = appl_ptr;
}

static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int trigger)
{
      struct snd_pcm_runtime *runtime;
      struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
      int err, cmd;

#ifdef OSS_DEBUG
      printk("pcm_oss: trigger = 0x%x\n", trigger);
#endif
      
      psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];

      if (psubstream) {
            if ((err = snd_pcm_oss_make_ready(psubstream)) < 0)
                  return err;
      }
      if (csubstream) {
            if ((err = snd_pcm_oss_make_ready(csubstream)) < 0)
                  return err;
      }
            if (psubstream) {
                  runtime = psubstream->runtime;
            if (trigger & PCM_ENABLE_OUTPUT) {
                  if (runtime->oss.trigger)
                        goto _skip1;
                  if (atomic_read(&psubstream->mmap_count))
                        snd_pcm_oss_simulate_fill(psubstream, runtime->hw_ptr_interrupt);
                  runtime->oss.trigger = 1;
                  runtime->start_threshold = 1;
                  cmd = SNDRV_PCM_IOCTL_START;
            } else {
                  if (!runtime->oss.trigger)
                        goto _skip1;
                  runtime->oss.trigger = 0;
                  runtime->start_threshold = runtime->boundary;
                  cmd = SNDRV_PCM_IOCTL_DROP;
                  runtime->oss.prepare = 1;
            }
            err = snd_pcm_kernel_ioctl(psubstream, cmd, NULL);
            if (err < 0)
                  return err;
      }
 _skip1:
      if (csubstream) {
                  runtime = csubstream->runtime;
            if (trigger & PCM_ENABLE_INPUT) {
                  if (runtime->oss.trigger)
                        goto _skip2;
                  runtime->oss.trigger = 1;
                  runtime->start_threshold = 1;
                  cmd = SNDRV_PCM_IOCTL_START;
            } else {
                  if (!runtime->oss.trigger)
                        goto _skip2;
                  runtime->oss.trigger = 0;
                  runtime->start_threshold = runtime->boundary;
                  cmd = SNDRV_PCM_IOCTL_DROP;
                  runtime->oss.prepare = 1;
            }
            err = snd_pcm_kernel_ioctl(csubstream, cmd, NULL);
            if (err < 0)
                  return err;
      }
 _skip2:
      return 0;
}

static int snd_pcm_oss_get_trigger(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
      int result = 0;

      psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
      if (psubstream && psubstream->runtime && psubstream->runtime->oss.trigger)
            result |= PCM_ENABLE_OUTPUT;
      if (csubstream && csubstream->runtime && csubstream->runtime->oss.trigger)
            result |= PCM_ENABLE_INPUT;
      return result;
}

static int snd_pcm_oss_get_odelay(struct snd_pcm_oss_file *pcm_oss_file)
{
      struct snd_pcm_substream *substream;
      struct snd_pcm_runtime *runtime;
      snd_pcm_sframes_t delay;
      int err;

      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      if (substream == NULL)
            return -EINVAL;
      if ((err = snd_pcm_oss_make_ready(substream)) < 0)
            return err;
      runtime = substream->runtime;
      if (runtime->oss.params || runtime->oss.prepare)
            return 0;
      err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
      if (err == -EPIPE)
            delay = 0;  /* hack for broken OSS applications */
      else if (err < 0)
            return err;
      return snd_pcm_oss_bytes(substream, delay);
}

static int snd_pcm_oss_get_ptr(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct count_info __user * _info)
{     
      struct snd_pcm_substream *substream;
      struct snd_pcm_runtime *runtime;
      snd_pcm_sframes_t delay;
      int fixup;
      struct count_info info;
      int err;

      if (_info == NULL)
            return -EFAULT;
      substream = pcm_oss_file->streams[stream];
      if (substream == NULL)
            return -EINVAL;
      if ((err = snd_pcm_oss_make_ready(substream)) < 0)
            return err;
      runtime = substream->runtime;
      if (runtime->oss.params || runtime->oss.prepare) {
            memset(&info, 0, sizeof(info));
            if (copy_to_user(_info, &info, sizeof(info)))
                  return -EFAULT;
            return 0;
      }
      if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
            err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
            if (err == -EPIPE || err == -ESTRPIPE || (! err && delay < 0)) {
                  err = 0;
                  delay = 0;
                  fixup = 0;
            } else {
                  fixup = runtime->oss.buffer_used;
            }
      } else {
            err = snd_pcm_oss_capture_position_fixup(substream, &delay);
            fixup = -runtime->oss.buffer_used;
      }
      if (err < 0)
            return err;
      info.ptr = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr % runtime->buffer_size);
      if (atomic_read(&substream->mmap_count)) {
            snd_pcm_sframes_t n;
            n = (delay = runtime->hw_ptr_interrupt) - runtime->oss.prev_hw_ptr_interrupt;
            if (n < 0)
                  n += runtime->boundary;
            info.blocks = n / runtime->period_size;
            runtime->oss.prev_hw_ptr_interrupt = delay;
            if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                  snd_pcm_oss_simulate_fill(substream, delay);
            info.bytes = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr) & INT_MAX;
      } else {
            delay = snd_pcm_oss_bytes(substream, delay);
            if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                  if (substream->oss.setup.buggyptr)
                        info.blocks = (runtime->oss.buffer_bytes - delay - fixup) / runtime->oss.period_bytes;
                  else
                        info.blocks = (delay + fixup) / runtime->oss.period_bytes;
                  info.bytes = (runtime->oss.bytes - delay) & INT_MAX;
            } else {
                  delay += fixup;
                  info.blocks = delay / runtime->oss.period_bytes;
                  info.bytes = (runtime->oss.bytes + delay) & INT_MAX;
            }
      }
      if (copy_to_user(_info, &info, sizeof(info)))
            return -EFAULT;
      return 0;
}

static int snd_pcm_oss_get_space(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct audio_buf_info __user *_info)
{
      struct snd_pcm_substream *substream;
      struct snd_pcm_runtime *runtime;
      snd_pcm_sframes_t avail;
      int fixup;
      struct audio_buf_info info;
      int err;

      if (_info == NULL)
            return -EFAULT;
      substream = pcm_oss_file->streams[stream];
      if (substream == NULL)
            return -EINVAL;
      runtime = substream->runtime;

      if (runtime->oss.params &&
          (err = snd_pcm_oss_change_params(substream)) < 0)
            return err;

      info.fragsize = runtime->oss.period_bytes;
      info.fragstotal = runtime->periods;
      if (runtime->oss.prepare) {
            if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                  info.bytes = runtime->oss.period_bytes * runtime->oss.periods;
                  info.fragments = runtime->oss.periods;
            } else {
                  info.bytes = 0;
                  info.fragments = 0;
            }
      } else {
            if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                  err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &avail);
                  if (err == -EPIPE || err == -ESTRPIPE || (! err && avail < 0)) {
                        avail = runtime->buffer_size;
                        err = 0;
                        fixup = 0;
                  } else {
                        avail = runtime->buffer_size - avail;
                        fixup = -runtime->oss.buffer_used;
                  }
            } else {
                  err = snd_pcm_oss_capture_position_fixup(substream, &avail);
                  fixup = runtime->oss.buffer_used;
            }
            if (err < 0)
                  return err;
            info.bytes = snd_pcm_oss_bytes(substream, avail) + fixup;
            info.fragments = info.bytes / runtime->oss.period_bytes;
      }

#ifdef OSS_DEBUG
      printk("pcm_oss: space: bytes = %i, fragments = %i, fragstotal = %i, fragsize = %i\n", info.bytes, info.fragments, info.fragstotal, info.fragsize);
#endif
      if (copy_to_user(_info, &info, sizeof(info)))
            return -EFAULT;
      return 0;
}

static int snd_pcm_oss_get_mapbuf(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct buffmem_desc __user * _info)
{
      // it won't be probably implemented
      // snd_printd("TODO: snd_pcm_oss_get_mapbuf\n");
      return -EINVAL;
}

static const char *strip_task_path(const char *path)
{
      const char *ptr, *ptrl = NULL;
      for (ptr = path; *ptr; ptr++) {
            if (*ptr == '/')
                  ptrl = ptr + 1;
      }
      return ptrl;
}

static void snd_pcm_oss_look_for_setup(struct snd_pcm *pcm, int stream,
                              const char *task_name,
                              struct snd_pcm_oss_setup *rsetup)
{
      struct snd_pcm_oss_setup *setup;

      mutex_lock(&pcm->streams[stream].oss.setup_mutex);
      do {
            for (setup = pcm->streams[stream].oss.setup_list; setup;
                 setup = setup->next) {
                  if (!strcmp(setup->task_name, task_name))
                        goto out;
            }
      } while ((task_name = strip_task_path(task_name)) != NULL);
 out:
      if (setup)
            *rsetup = *setup;
      mutex_unlock(&pcm->streams[stream].oss.setup_mutex);
}

static void snd_pcm_oss_release_substream(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime;
      runtime = substream->runtime;
      vfree(runtime->oss.buffer);
      runtime->oss.buffer = NULL;
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
      snd_pcm_oss_plugin_clear(substream);
#endif
      substream->oss.oss = 0;
}

static void snd_pcm_oss_init_substream(struct snd_pcm_substream *substream,
                               struct snd_pcm_oss_setup *setup,
                               int minor)
{
      struct snd_pcm_runtime *runtime;

      substream->oss.oss = 1;
      substream->oss.setup = *setup;
      if (setup->nonblock)
            substream->f_flags |= O_NONBLOCK;
      else if (setup->block)
            substream->f_flags &= ~O_NONBLOCK;
      runtime = substream->runtime;
      runtime->oss.params = 1;
      runtime->oss.trigger = 1;
      runtime->oss.rate = 8000;
      mutex_init(&runtime->oss.params_lock);
      switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
      case SNDRV_MINOR_OSS_PCM_8:
            runtime->oss.format = AFMT_U8;
            break;
      case SNDRV_MINOR_OSS_PCM_16:
            runtime->oss.format = AFMT_S16_LE;
            break;
      default:
            runtime->oss.format = AFMT_MU_LAW;
      }
      runtime->oss.channels = 1;
      runtime->oss.fragshift = 0;
      runtime->oss.maxfrags = 0;
      runtime->oss.subdivision = 0;
      substream->pcm_release = snd_pcm_oss_release_substream;
}

static int snd_pcm_oss_release_file(struct snd_pcm_oss_file *pcm_oss_file)
{
      int cidx;
      snd_assert(pcm_oss_file != NULL, return -ENXIO);
      for (cidx = 0; cidx < 2; ++cidx) {
            struct snd_pcm_substream *substream = pcm_oss_file->streams[cidx];
            if (substream)
                  snd_pcm_release_substream(substream);
      }
      kfree(pcm_oss_file);
      return 0;
}

static int snd_pcm_oss_open_file(struct file *file,
                         struct snd_pcm *pcm,
                         struct snd_pcm_oss_file **rpcm_oss_file,
                         int minor,
                         struct snd_pcm_oss_setup *setup)
{
      int idx, err;
      struct snd_pcm_oss_file *pcm_oss_file;
      struct snd_pcm_substream *substream;
      unsigned int f_mode = file->f_mode;

      snd_assert(rpcm_oss_file != NULL, return -EINVAL);
      *rpcm_oss_file = NULL;

      pcm_oss_file = kzalloc(sizeof(*pcm_oss_file), GFP_KERNEL);
      if (pcm_oss_file == NULL)
            return -ENOMEM;

      if ((f_mode & (FMODE_WRITE|FMODE_READ)) == (FMODE_WRITE|FMODE_READ) &&
          (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX))
            f_mode = FMODE_WRITE;

      file->f_flags &= ~O_APPEND;
      for (idx = 0; idx < 2; idx++) {
            if (setup[idx].disable)
                  continue;
            if (! pcm->streams[idx].substream_count)
                  continue; /* no matching substream */
            if (idx == SNDRV_PCM_STREAM_PLAYBACK) {
                  if (! (f_mode & FMODE_WRITE))
                        continue;
            } else {
                  if (! (f_mode & FMODE_READ))
                        continue;
            }
            err = snd_pcm_open_substream(pcm, idx, file, &substream);
            if (err < 0) {
                  snd_pcm_oss_release_file(pcm_oss_file);
                  return err;
            }

            pcm_oss_file->streams[idx] = substream;
            substream->file = pcm_oss_file;
            snd_pcm_oss_init_substream(substream, &setup[idx], minor);
      }
      
      if (!pcm_oss_file->streams[0] && !pcm_oss_file->streams[1]) {
            snd_pcm_oss_release_file(pcm_oss_file);
            return -EINVAL;
      }

      file->private_data = pcm_oss_file;
      *rpcm_oss_file = pcm_oss_file;
      return 0;
}


static int snd_task_name(struct task_struct *task, char *name, size_t size)
{
      unsigned int idx;

      snd_assert(task != NULL && name != NULL && size >= 2, return -EINVAL);
      for (idx = 0; idx < sizeof(task->comm) && idx + 1 < size; idx++)
            name[idx] = task->comm[idx];
      name[idx] = '\0';
      return 0;
}

static int snd_pcm_oss_open(struct inode *inode, struct file *file)
{
      int err;
      char task_name[32];
      struct snd_pcm *pcm;
      struct snd_pcm_oss_file *pcm_oss_file;
      struct snd_pcm_oss_setup setup[2];
      int nonblock;
      wait_queue_t wait;

      pcm = snd_lookup_oss_minor_data(iminor(inode),
                              SNDRV_OSS_DEVICE_TYPE_PCM);
      if (pcm == NULL) {
            err = -ENODEV;
            goto __error1;
      }
      err = snd_card_file_add(pcm->card, file);
      if (err < 0)
            goto __error1;
      if (!try_module_get(pcm->card->module)) {
            err = -EFAULT;
            goto __error2;
      }
      if (snd_task_name(current, task_name, sizeof(task_name)) < 0) {
            err = -EFAULT;
            goto __error;
      }
      memset(setup, 0, sizeof(setup));
      if (file->f_mode & FMODE_WRITE)
            snd_pcm_oss_look_for_setup(pcm, SNDRV_PCM_STREAM_PLAYBACK,
                                 task_name, &setup[0]);
      if (file->f_mode & FMODE_READ)
            snd_pcm_oss_look_for_setup(pcm, SNDRV_PCM_STREAM_CAPTURE,
                                 task_name, &setup[1]);

      nonblock = !!(file->f_flags & O_NONBLOCK);
      if (!nonblock)
            nonblock = nonblock_open;

      init_waitqueue_entry(&wait, current);
      add_wait_queue(&pcm->open_wait, &wait);
      mutex_lock(&pcm->open_mutex);
      while (1) {
            err = snd_pcm_oss_open_file(file, pcm, &pcm_oss_file,
                                  iminor(inode), setup);
            if (err >= 0)
                  break;
            if (err == -EAGAIN) {
                  if (nonblock) {
                        err = -EBUSY;
                        break;
                  }
            } else
                  break;
            set_current_state(TASK_INTERRUPTIBLE);
            mutex_unlock(&pcm->open_mutex);
            schedule();
            mutex_lock(&pcm->open_mutex);
            if (signal_pending(current)) {
                  err = -ERESTARTSYS;
                  break;
            }
      }
      remove_wait_queue(&pcm->open_wait, &wait);
      mutex_unlock(&pcm->open_mutex);
      if (err < 0)
            goto __error;
      return err;

      __error:
      module_put(pcm->card->module);
      __error2:
            snd_card_file_remove(pcm->card, file);
      __error1:
      return err;
}

static int snd_pcm_oss_release(struct inode *inode, struct file *file)
{
      struct snd_pcm *pcm;
      struct snd_pcm_substream *substream;
      struct snd_pcm_oss_file *pcm_oss_file;

      pcm_oss_file = file->private_data;
      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      if (substream == NULL)
            substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
      snd_assert(substream != NULL, return -ENXIO);
      pcm = substream->pcm;
      if (!pcm->card->shutdown)
            snd_pcm_oss_sync(pcm_oss_file);
      mutex_lock(&pcm->open_mutex);
      snd_pcm_oss_release_file(pcm_oss_file);
      mutex_unlock(&pcm->open_mutex);
      wake_up(&pcm->open_wait);
      module_put(pcm->card->module);
      snd_card_file_remove(pcm->card, file);
      return 0;
}

static long snd_pcm_oss_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
      struct snd_pcm_oss_file *pcm_oss_file;
      int __user *p = (int __user *)arg;
      int res;

      pcm_oss_file = file->private_data;
      if (cmd == OSS_GETVERSION)
            return put_user(SNDRV_OSS_VERSION, p);
      if (cmd == OSS_ALSAEMULVER)
            return put_user(1, p);
#if defined(CONFIG_SND_MIXER_OSS) || (defined(MODULE) && defined(CONFIG_SND_MIXER_OSS_MODULE))
      if (((cmd >> 8) & 0xff) == 'M')     {     /* mixer ioctl - for OSS compatibility */
            struct snd_pcm_substream *substream;
            int idx;
            for (idx = 0; idx < 2; ++idx) {
                  substream = pcm_oss_file->streams[idx];
                  if (substream != NULL)
                        break;
            }
            snd_assert(substream != NULL, return -ENXIO);
            return snd_mixer_oss_ioctl_card(substream->pcm->card, cmd, arg);
      }
#endif
      if (((cmd >> 8) & 0xff) != 'P')
            return -EINVAL;
#ifdef OSS_DEBUG
      printk("pcm_oss: ioctl = 0x%x\n", cmd);
#endif
      switch (cmd) {
      case SNDCTL_DSP_RESET:
            return snd_pcm_oss_reset(pcm_oss_file);
      case SNDCTL_DSP_SYNC:
            return snd_pcm_oss_sync(pcm_oss_file);
      case SNDCTL_DSP_SPEED:
            if (get_user(res, p))
                  return -EFAULT;
            if ((res = snd_pcm_oss_set_rate(pcm_oss_file, res))<0)
                  return res;
            return put_user(res, p);
      case SOUND_PCM_READ_RATE:
            res = snd_pcm_oss_get_rate(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_STEREO:
            if (get_user(res, p))
                  return -EFAULT;
            res = res > 0 ? 2 : 1;
            if ((res = snd_pcm_oss_set_channels(pcm_oss_file, res)) < 0)
                  return res;
            return put_user(--res, p);
      case SNDCTL_DSP_GETBLKSIZE:
            res = snd_pcm_oss_get_block_size(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_SETFMT:
            if (get_user(res, p))
                  return -EFAULT;
            res = snd_pcm_oss_set_format(pcm_oss_file, res);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SOUND_PCM_READ_BITS:
            res = snd_pcm_oss_get_format(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_CHANNELS:
            if (get_user(res, p))
                  return -EFAULT;
            res = snd_pcm_oss_set_channels(pcm_oss_file, res);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SOUND_PCM_READ_CHANNELS:
            res = snd_pcm_oss_get_channels(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SOUND_PCM_WRITE_FILTER:
      case SOUND_PCM_READ_FILTER:
            return -EIO;
      case SNDCTL_DSP_POST:
            return snd_pcm_oss_post(pcm_oss_file);
      case SNDCTL_DSP_SUBDIVIDE:
            if (get_user(res, p))
                  return -EFAULT;
            res = snd_pcm_oss_set_subdivide(pcm_oss_file, res);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_SETFRAGMENT:
            if (get_user(res, p))
                  return -EFAULT;
            return snd_pcm_oss_set_fragment(pcm_oss_file, res);
      case SNDCTL_DSP_GETFMTS:
            res = snd_pcm_oss_get_formats(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_GETOSPACE:
      case SNDCTL_DSP_GETISPACE:
            return snd_pcm_oss_get_space(pcm_oss_file,
                  cmd == SNDCTL_DSP_GETISPACE ?
                        SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK,
                  (struct audio_buf_info __user *) arg);
      case SNDCTL_DSP_NONBLOCK:
            return snd_pcm_oss_nonblock(file);
      case SNDCTL_DSP_GETCAPS:
            res = snd_pcm_oss_get_caps(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_GETTRIGGER:
            res = snd_pcm_oss_get_trigger(pcm_oss_file);
            if (res < 0)
                  return res;
            return put_user(res, p);
      case SNDCTL_DSP_SETTRIGGER:
            if (get_user(res, p))
                  return -EFAULT;
            return snd_pcm_oss_set_trigger(pcm_oss_file, res);
      case SNDCTL_DSP_GETIPTR:
      case SNDCTL_DSP_GETOPTR:
            return snd_pcm_oss_get_ptr(pcm_oss_file,
                  cmd == SNDCTL_DSP_GETIPTR ?
                        SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK,
                  (struct count_info __user *) arg);
      case SNDCTL_DSP_MAPINBUF:
      case SNDCTL_DSP_MAPOUTBUF:
            return snd_pcm_oss_get_mapbuf(pcm_oss_file,
                  cmd == SNDCTL_DSP_MAPINBUF ?
                        SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK,
                  (struct buffmem_desc __user *) arg);
      case SNDCTL_DSP_SETSYNCRO:
            /* stop DMA now.. */
            return 0;
      case SNDCTL_DSP_SETDUPLEX:
            if (snd_pcm_oss_get_caps(pcm_oss_file) & DSP_CAP_DUPLEX)
                  return 0;
            return -EIO;
      case SNDCTL_DSP_GETODELAY:
            res = snd_pcm_oss_get_odelay(pcm_oss_file);
            if (res < 0) {
                  /* it's for sure, some broken apps don't check for error codes */
                  put_user(0, p);
                  return res;
            }
            return put_user(res, p);
      case SNDCTL_DSP_PROFILE:
            return 0;   /* silently ignore */
      default:
            snd_printd("pcm_oss: unknown command = 0x%x\n", cmd);
      }
      return -EINVAL;
}

#ifdef CONFIG_COMPAT
/* all compatible */
#define snd_pcm_oss_ioctl_compat    snd_pcm_oss_ioctl
#else
#define snd_pcm_oss_ioctl_compat    NULL
#endif

static ssize_t snd_pcm_oss_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
      struct snd_pcm_oss_file *pcm_oss_file;
      struct snd_pcm_substream *substream;

      pcm_oss_file = file->private_data;
      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
      if (substream == NULL)
            return -ENXIO;
      substream->f_flags = file->f_flags & O_NONBLOCK;
#ifndef OSS_DEBUG
      return snd_pcm_oss_read1(substream, buf, count);
#else
      {
            ssize_t res = snd_pcm_oss_read1(substream, buf, count);
            printk("pcm_oss: read %li bytes (returned %li bytes)\n", (long)count, (long)res);
            return res;
      }
#endif
}

static ssize_t snd_pcm_oss_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
{
      struct snd_pcm_oss_file *pcm_oss_file;
      struct snd_pcm_substream *substream;
      long result;

      pcm_oss_file = file->private_data;
      substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      if (substream == NULL)
            return -ENXIO;
      substream->f_flags = file->f_flags & O_NONBLOCK;
      result = snd_pcm_oss_write1(substream, buf, count);
#ifdef OSS_DEBUG
      printk("pcm_oss: write %li bytes (wrote %li bytes)\n", (long)count, (long)result);
#endif
      return result;
}

static int snd_pcm_oss_playback_ready(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      if (atomic_read(&substream->mmap_count))
            return runtime->oss.prev_hw_ptr_interrupt != runtime->hw_ptr_interrupt;
      else
            return snd_pcm_playback_avail(runtime) >= runtime->oss.period_frames;
}

static int snd_pcm_oss_capture_ready(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      if (atomic_read(&substream->mmap_count))
            return runtime->oss.prev_hw_ptr_interrupt != runtime->hw_ptr_interrupt;
      else
            return snd_pcm_capture_avail(runtime) >= runtime->oss.period_frames;
}

static unsigned int snd_pcm_oss_poll(struct file *file, poll_table * wait)
{
      struct snd_pcm_oss_file *pcm_oss_file;
      unsigned int mask;
      struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
      
      pcm_oss_file = file->private_data;

      psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
      csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];

      mask = 0;
      if (psubstream != NULL) {
            struct snd_pcm_runtime *runtime = psubstream->runtime;
            poll_wait(file, &runtime->sleep, wait);
            snd_pcm_stream_lock_irq(psubstream);
            if (runtime->status->state != SNDRV_PCM_STATE_DRAINING &&
                (runtime->status->state != SNDRV_PCM_STATE_RUNNING ||
                 snd_pcm_oss_playback_ready(psubstream)))
                  mask |= POLLOUT | POLLWRNORM;
            snd_pcm_stream_unlock_irq(psubstream);
      }
      if (csubstream != NULL) {
            struct snd_pcm_runtime *runtime = csubstream->runtime;
            snd_pcm_state_t ostate;
            poll_wait(file, &runtime->sleep, wait);
            snd_pcm_stream_lock_irq(csubstream);
            if ((ostate = runtime->status->state) != SNDRV_PCM_STATE_RUNNING ||
                snd_pcm_oss_capture_ready(csubstream))
                  mask |= POLLIN | POLLRDNORM;
            snd_pcm_stream_unlock_irq(csubstream);
            if (ostate != SNDRV_PCM_STATE_RUNNING && runtime->oss.trigger) {
                  struct snd_pcm_oss_file ofile;
                  memset(&ofile, 0, sizeof(ofile));
                  ofile.streams[SNDRV_PCM_STREAM_CAPTURE] = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
                  runtime->oss.trigger = 0;
                  snd_pcm_oss_set_trigger(&ofile, PCM_ENABLE_INPUT);
            }
      }

      return mask;
}

static int snd_pcm_oss_mmap(struct file *file, struct vm_area_struct *area)
{
      struct snd_pcm_oss_file *pcm_oss_file;
      struct snd_pcm_substream *substream = NULL;
      struct snd_pcm_runtime *runtime;
      int err;

#ifdef OSS_DEBUG
      printk("pcm_oss: mmap begin\n");
#endif
      pcm_oss_file = file->private_data;
      switch ((area->vm_flags & (VM_READ | VM_WRITE))) {
      case VM_READ | VM_WRITE:
            substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
            if (substream)
                  break;
            /* Fall through */
      case VM_READ:
            substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
            break;
      case VM_WRITE:
            substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
            break;
      default:
            return -EINVAL;
      }
      /* set VM_READ access as well to fix memset() routines that do
         reads before writes (to improve performance) */
      area->vm_flags |= VM_READ;
      if (substream == NULL)
            return -ENXIO;
      runtime = substream->runtime;
      if (!(runtime->info & SNDRV_PCM_INFO_MMAP_VALID))
            return -EIO;
      if (runtime->info & SNDRV_PCM_INFO_INTERLEAVED)
            runtime->access = SNDRV_PCM_ACCESS_MMAP_INTERLEAVED;
      else
            return -EIO;
      
      if (runtime->oss.params) {
            if ((err = snd_pcm_oss_change_params(substream)) < 0)
                  return err;
      }
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
      if (runtime->oss.plugin_first != NULL)
            return -EIO;
#endif

      if (area->vm_pgoff != 0)
            return -EINVAL;

      err = snd_pcm_mmap_data(substream, file, area);
      if (err < 0)
            return err;
      runtime->oss.mmap_bytes = area->vm_end - area->vm_start;
      runtime->silence_threshold = 0;
      runtime->silence_size = 0;
#ifdef OSS_DEBUG
      printk("pcm_oss: mmap ok, bytes = 0x%x\n", runtime->oss.mmap_bytes);
#endif
      /* In mmap mode we never stop */
      runtime->stop_threshold = runtime->boundary;

      return 0;
}

#ifdef CONFIG_SND_VERBOSE_PROCFS
/*
 *  /proc interface
 */

static void snd_pcm_oss_proc_read(struct snd_info_entry *entry,
                          struct snd_info_buffer *buffer)
{
      struct snd_pcm_str *pstr = entry->private_data;
      struct snd_pcm_oss_setup *setup = pstr->oss.setup_list;
      mutex_lock(&pstr->oss.setup_mutex);
      while (setup) {
            snd_iprintf(buffer, "%s %u %u%s%s%s%s%s%s\n",
                      setup->task_name,
                      setup->periods,
                      setup->period_size,
                      setup->disable ? " disable" : "",
                      setup->direct ? " direct" : "",
                      setup->block ? " block" : "",
                      setup->nonblock ? " non-block" : "",
                      setup->partialfrag ? " partial-frag" : "",
                      setup->nosilence ? " no-silence" : "");
            setup = setup->next;
      }
      mutex_unlock(&pstr->oss.setup_mutex);
}

static void snd_pcm_oss_proc_free_setup_list(struct snd_pcm_str * pstr)
{
      struct snd_pcm_oss_setup *setup, *setupn;

      for (setup = pstr->oss.setup_list, pstr->oss.setup_list = NULL;
           setup; setup = setupn) {
            setupn = setup->next;
            kfree(setup->task_name);
            kfree(setup);
      }
      pstr->oss.setup_list = NULL;
}

static void snd_pcm_oss_proc_write(struct snd_info_entry *entry,
                           struct snd_info_buffer *buffer)
{
      struct snd_pcm_str *pstr = entry->private_data;
      char line[128], str[32], task_name[32], *ptr;
      int idx1;
      struct snd_pcm_oss_setup *setup, *setup1, template;

      while (!snd_info_get_line(buffer, line, sizeof(line))) {
            mutex_lock(&pstr->oss.setup_mutex);
            memset(&template, 0, sizeof(template));
            ptr = snd_info_get_str(task_name, line, sizeof(task_name));
            if (!strcmp(task_name, "clear") || !strcmp(task_name, "erase")) {
                  snd_pcm_oss_proc_free_setup_list(pstr);
                  mutex_unlock(&pstr->oss.setup_mutex);
                  continue;
            }
            for (setup = pstr->oss.setup_list; setup; setup = setup->next) {
                  if (!strcmp(setup->task_name, task_name)) {
                        template = *setup;
                        break;
                  }
            }
            ptr = snd_info_get_str(str, ptr, sizeof(str));
            template.periods = simple_strtoul(str, NULL, 10);
            ptr = snd_info_get_str(str, ptr, sizeof(str));
            template.period_size = simple_strtoul(str, NULL, 10);
            for (idx1 = 31; idx1 >= 0; idx1--)
                  if (template.period_size & (1 << idx1))
                        break;
            for (idx1--; idx1 >= 0; idx1--)
                  template.period_size &= ~(1 << idx1);
            do {
                  ptr = snd_info_get_str(str, ptr, sizeof(str));
                  if (!strcmp(str, "disable")) {
                        template.disable = 1;
                  } else if (!strcmp(str, "direct")) {
                        template.direct = 1;
                  } else if (!strcmp(str, "block")) {
                        template.block = 1;
                  } else if (!strcmp(str, "non-block")) {
                        template.nonblock = 1;
                  } else if (!strcmp(str, "partial-frag")) {
                        template.partialfrag = 1;
                  } else if (!strcmp(str, "no-silence")) {
                        template.nosilence = 1;
                  } else if (!strcmp(str, "buggy-ptr")) {
                        template.buggyptr = 1;
                  }
            } while (*str);
            if (setup == NULL) {
                  setup = kmalloc(sizeof(*setup), GFP_KERNEL);
                  if (! setup) {
                        buffer->error = -ENOMEM;
                        mutex_lock(&pstr->oss.setup_mutex);
                        return;
                  }
                  if (pstr->oss.setup_list == NULL)
                        pstr->oss.setup_list = setup;
                  else {
                        for (setup1 = pstr->oss.setup_list;
                             setup1->next; setup1 = setup1->next);
                        setup1->next = setup;
                  }
                  template.task_name = kstrdup(task_name, GFP_KERNEL);
                  if (! template.task_name) {
                        kfree(setup);
                        buffer->error = -ENOMEM;
                        mutex_lock(&pstr->oss.setup_mutex);
                        return;
                  }
            }
            *setup = template;
            mutex_unlock(&pstr->oss.setup_mutex);
      }
}

static void snd_pcm_oss_proc_init(struct snd_pcm *pcm)
{
      int stream;
      for (stream = 0; stream < 2; ++stream) {
            struct snd_info_entry *entry;
            struct snd_pcm_str *pstr = &pcm->streams[stream];
            if (pstr->substream_count == 0)
                  continue;
            if ((entry = snd_info_create_card_entry(pcm->card, "oss", pstr->proc_root)) != NULL) {
                  entry->content = SNDRV_INFO_CONTENT_TEXT;
                  entry->mode = S_IFREG | S_IRUGO | S_IWUSR;
                  entry->c.text.read = snd_pcm_oss_proc_read;
                  entry->c.text.write = snd_pcm_oss_proc_write;
                  entry->private_data = pstr;
                  if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                  }
            }
            pstr->oss.proc_entry = entry;
      }
}

static void snd_pcm_oss_proc_done(struct snd_pcm *pcm)
{
      int stream;
      for (stream = 0; stream < 2; ++stream) {
            struct snd_pcm_str *pstr = &pcm->streams[stream];
            snd_info_free_entry(pstr->oss.proc_entry);
            pstr->oss.proc_entry = NULL;
            snd_pcm_oss_proc_free_setup_list(pstr);
      }
}
#else /* !CONFIG_SND_VERBOSE_PROCFS */
#define snd_pcm_oss_proc_init(pcm)
#define snd_pcm_oss_proc_done(pcm)
#endif /* CONFIG_SND_VERBOSE_PROCFS */

/*
 *  ENTRY functions
 */

static const struct file_operations snd_pcm_oss_f_reg =
{
      .owner =    THIS_MODULE,
      .read =           snd_pcm_oss_read,
      .write =    snd_pcm_oss_write,
      .open =           snd_pcm_oss_open,
      .release =  snd_pcm_oss_release,
      .poll =           snd_pcm_oss_poll,
      .unlocked_ioctl = snd_pcm_oss_ioctl,
      .compat_ioctl =   snd_pcm_oss_ioctl_compat,
      .mmap =           snd_pcm_oss_mmap,
};

static void register_oss_dsp(struct snd_pcm *pcm, int index)
{
      char name[128];
      sprintf(name, "dsp%i%i", pcm->card->number, pcm->device);
      if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
                            pcm->card, index, &snd_pcm_oss_f_reg,
                            pcm, name) < 0) {
            snd_printk(KERN_ERR "unable to register OSS PCM device %i:%i\n",
                     pcm->card->number, pcm->device);
      }
}

static int snd_pcm_oss_register_minor(struct snd_pcm *pcm)
{
      pcm->oss.reg = 0;
      if (dsp_map[pcm->card->number] == (int)pcm->device) {
            char name[128];
            int duplex;
            register_oss_dsp(pcm, 0);
            duplex = (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count > 0 && 
                        pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count && 
                        !(pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX));
            sprintf(name, "%s%s", pcm->name, duplex ? " (DUPLEX)" : "");
#ifdef SNDRV_OSS_INFO_DEV_AUDIO
            snd_oss_info_register(SNDRV_OSS_INFO_DEV_AUDIO,
                              pcm->card->number,
                              name);
#endif
            pcm->oss.reg++;
            pcm->oss.reg_mask |= 1;
      }
      if (adsp_map[pcm->card->number] == (int)pcm->device) {
            register_oss_dsp(pcm, 1);
            pcm->oss.reg++;
            pcm->oss.reg_mask |= 2;
      }

      if (pcm->oss.reg)
            snd_pcm_oss_proc_init(pcm);

      return 0;
}

static int snd_pcm_oss_disconnect_minor(struct snd_pcm *pcm)
{
      if (pcm->oss.reg) {
            if (pcm->oss.reg_mask & 1) {
                  pcm->oss.reg_mask &= ~1;
                  snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
                                      pcm->card, 0);
            }
            if (pcm->oss.reg_mask & 2) {
                  pcm->oss.reg_mask &= ~2;
                  snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
                                      pcm->card, 1);
            }
            if (dsp_map[pcm->card->number] == (int)pcm->device) {
#ifdef SNDRV_OSS_INFO_DEV_AUDIO
                  snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_AUDIO, pcm->card->number);
#endif
            }
            pcm->oss.reg = 0;
      }
      return 0;
}

static int snd_pcm_oss_unregister_minor(struct snd_pcm *pcm)
{
      snd_pcm_oss_disconnect_minor(pcm);
      snd_pcm_oss_proc_done(pcm);
      return 0;
}

static struct snd_pcm_notify snd_pcm_oss_notify =
{
      .n_register =     snd_pcm_oss_register_minor,
      .n_disconnect = snd_pcm_oss_disconnect_minor,
      .n_unregister =   snd_pcm_oss_unregister_minor,
};

static int __init alsa_pcm_oss_init(void)
{
      int i;
      int err;

      /* check device map table */
      for (i = 0; i < SNDRV_CARDS; i++) {
            if (dsp_map[i] < 0 || dsp_map[i] >= SNDRV_PCM_DEVICES) {
                  snd_printk(KERN_ERR "invalid dsp_map[%d] = %d\n",
                           i, dsp_map[i]);
                  dsp_map[i] = 0;
            }
            if (adsp_map[i] < 0 || adsp_map[i] >= SNDRV_PCM_DEVICES) {
                  snd_printk(KERN_ERR "invalid adsp_map[%d] = %d\n",
                           i, adsp_map[i]);
                  adsp_map[i] = 1;
            }
      }
      if ((err = snd_pcm_notify(&snd_pcm_oss_notify, 0)) < 0)
            return err;
      return 0;
}

static void __exit alsa_pcm_oss_exit(void)
{
      snd_pcm_notify(&snd_pcm_oss_notify, 1);
}

module_init(alsa_pcm_oss_init)
module_exit(alsa_pcm_oss_exit)

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