Commit message: ALSA: pcm : Call kill_fasync() in stream lock

Currently kill_fasync() is called outside the stream lock in
snd_pcm_period_elapsed().  This is potentially racy, since the stream
may get released even during the irq handler is running.  Although
snd_pcm_release_substream() calls snd_pcm_drop(), this doesn't
guarantee that the irq handler finishes, thus the kill_fasync() call
outside the stream spin lock may be invoked after the substream is
detached, as recently reported by KASAN.

As a quick workaround, move kill_fasync() call inside the stream
lock.  The fasync is rarely used interface, so this shouldn't have a
big impact from the performance POV.

Ideally, we should implement some sync mechanism for the proper finish
of stream and irq handler.  But this oneliner should suffice for most
cases, so far.

Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
CVE: CVE-2016-9794
CWE: CWE-416
Vulnerability description: Race condition in the snd_pcm_period_elapsed function in sound/core/pcm_lib.c in the ALSA subsystem in the Linux kernel before 4.7 allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted SNDRV_PCM_TRIGGER_START command.

Project: linux
File: pcm_lib.c

static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
				  snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var)) {
		snd_mask_any(hw_param_mask(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	if (hw_is_interval(var)) {
		snd_interval_any(hw_param_interval(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	snd_BUG();
}

Project: linux
File: pcm_lib.c

static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
				   snd_pcm_hw_param_t var)
{
	int changed;
	if (hw_is_mask(var))
		changed = snd_mask_refine_first(hw_param_mask(params, var));
	else if (hw_is_interval(var))
		changed = snd_interval_refine_first(hw_param_interval(params, var));
	else
		return -EINVAL;
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

Project: linux
File: pcm_lib.c

static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
				  snd_pcm_hw_param_t var)
{
	int changed;
	if (hw_is_mask(var))
		changed = snd_mask_refine_last(hw_param_mask(params, var));
	else if (hw_is_interval(var))
		changed = snd_interval_refine_last(hw_param_interval(params, var));
	else
		return -EINVAL;
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

Project: linux
File: pcm_lib.c

void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
{
	unsigned int k;
	memset(params, 0, sizeof(*params));
	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
		_snd_pcm_hw_param_any(params, k);
	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
		_snd_pcm_hw_param_any(params, k);
	params->info = ~0U;
}

Project: linux
File: pcm_lib.c

static inline unsigned int div32(unsigned int a, unsigned int b, 
				 unsigned int *r)
{
	if (b == 0) {
		*r = 0;
		return UINT_MAX;
	}
	*r = a % b;
	return a / b;
}

Project: linux
File: pcm_lib.c

static inline unsigned int div_down(unsigned int a, unsigned int b)
{
	if (b == 0)
		return UINT_MAX;
	return a / b;
}

Project: linux
File: pcm_lib.c

static inline unsigned int mul(unsigned int a, unsigned int b)
{
	if (a == 0)
		return 0;
	if (div_down(UINT_MAX, a) < b)
		return UINT_MAX;
	return a * b;
}

Project: linux
File: pcm_lib.c

static inline unsigned int muldiv32(unsigned int a, unsigned int b,
				    unsigned int c, unsigned int *r)
{
	u_int64_t n = (u_int64_t) a * b;
	if (c == 0) {
		snd_BUG_ON(!n);
		*r = 0;
		return UINT_MAX;
	}
	n = div_u64_rem(n, c, r);
	if (n >= UINT_MAX) {
		*r = 0;
		return UINT_MAX;
	}
	return n;
}

Project: linux
File: pcm_lib.c

static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
			      struct snd_ctl_elem_info *uinfo)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);

	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
	uinfo->count = 0;
	uinfo->count = info->max_channels;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
	return 0;
}

Project: linux
File: pcm_lib.c

static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
			     unsigned int size, unsigned int __user *tlv)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
	const struct snd_pcm_chmap_elem *map;
	unsigned int __user *dst;
	int c, count = 0;

	if (snd_BUG_ON(!info->chmap))
		return -EINVAL;
	if (size < 8)
		return -ENOMEM;
	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
		return -EFAULT;
	size -= 8;
	dst = tlv + 2;
	for (map = info->chmap; map->channels; map++) {
		int chs_bytes = map->channels * 4;
		if (!valid_chmap_channels(info, map->channels))
			continue;
		if (size < 8)
			return -ENOMEM;
		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
		    put_user(chs_bytes, dst + 1))
			return -EFAULT;
		dst += 2;
		size -= 8;
		count += 8;
		if (size < chs_bytes)
			return -ENOMEM;
		size -= chs_bytes;
		count += chs_bytes;
		for (c = 0; c < map->channels; c++) {
			if (put_user(map->map[c], dst))
				return -EFAULT;
			dst++;
		}
	}
	if (put_user(count, tlv + 1))
		return -EFAULT;
	return 0;
}

Project: linux
File: pcm_lib.c

static int pcm_sanity_check(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;
	if (PCM_RUNTIME_CHECK(substream))
		return -ENXIO;
	runtime = substream->runtime;
	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
		return -EINVAL;
	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
		return -EBADFD;
	return 0;
}

Project: linux
File: pcm_lib.c

int snd_interval_list(struct snd_interval *i, unsigned int count,
		      const unsigned int *list, unsigned int mask)
{
        unsigned int k;
	struct snd_interval list_range;

	if (!count) {
		i->empty = 1;
		return -EINVAL;
	}
	snd_interval_any(&list_range);
	list_range.min = UINT_MAX;
	list_range.max = 0;
        for (k = 0; k < count; k++) {
		if (mask && !(mask & (1 << k)))
			continue;
		if (!snd_interval_test(i, list[k]))
			continue;
		list_range.min = min(list_range.min, list[k]);
		list_range.max = max(list_range.max, list[k]);
        }
	return snd_interval_refine(i, &list_range);
}

Project: linux
File: pcm_lib.c

void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
{
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = mul(a->min, b->min);
	c->openmin = (a->openmin || b->openmin);
	c->max = mul(a->max,  b->max);
	c->openmax = (a->openmax || b->openmax);
	c->integer = (a->integer && b->integer);
}

Project: linux
File: pcm_lib.c

void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
		      unsigned int k, struct snd_interval *c)
{
	unsigned int r;
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = muldiv32(a->min, b->min, k, &r);
	c->openmin = (r || a->openmin || b->openmin);
	c->max = muldiv32(a->max, b->max, k, &r);
	if (r) {
		c->max++;
		c->openmax = 1;
	} else
		c->openmax = (a->openmax || b->openmax);
	c->integer = 0;
}

Project: linux
File: pcm_lib.c

void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
		      const struct snd_interval *b, struct snd_interval *c)
{
	unsigned int r;
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = muldiv32(a->min, k, b->max, &r);
	c->openmin = (r || a->openmin || b->openmax);
	if (b->min > 0) {
		c->max = muldiv32(a->max, k, b->min, &r);
		if (r) {
			c->max++;
			c->openmax = 1;
		} else
			c->openmax = (a->openmax || b->openmin);
	} else {
		c->max = UINT_MAX;
		c->openmax = 0;
	}
	c->integer = 0;
}

Project: linux
File: pcm_lib.c

int snd_interval_ranges(struct snd_interval *i, unsigned int count,
			const struct snd_interval *ranges, unsigned int mask)
{
	unsigned int k;
	struct snd_interval range_union;
	struct snd_interval range;

	if (!count) {
		snd_interval_none(i);
		return -EINVAL;
	}
	snd_interval_any(&range_union);
	range_union.min = UINT_MAX;
	range_union.max = 0;
	for (k = 0; k < count; k++) {
		if (mask && !(mask & (1 << k)))
			continue;
		snd_interval_copy(&range, &ranges[k]);
		if (snd_interval_refine(&range, i) < 0)
			continue;
		if (snd_interval_empty(&range))
			continue;

		if (range.min < range_union.min) {
			range_union.min = range.min;
			range_union.openmin = 1;
		}
		if (range.min == range_union.min && !range.openmin)
			range_union.openmin = 0;
		if (range.max > range_union.max) {
			range_union.max = range.max;
			range_union.openmax = 1;
		}
		if (range.max == range_union.max && !range.openmax)
			range_union.openmax = 0;
	}
	return snd_interval_refine(i, &range_union);
}

Project: linux
File: pcm_lib.c

static int snd_interval_ratden(struct snd_interval *i,
			       unsigned int rats_count,
			       const struct snd_ratden *rats,
			       unsigned int *nump, unsigned int *denp)
{
	unsigned int best_num, best_diff, best_den;
	unsigned int k;
	struct snd_interval t;
	int err;

	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num;
		unsigned int den = rats[k].den;
		unsigned int q = i->min;
		int diff;
		num = mul(q, den);
		if (num > rats[k].num_max)
			continue;
		if (num < rats[k].num_min)
			num = rats[k].num_max;
		else {
			unsigned int r;
			r = (num - rats[k].num_min) % rats[k].num_step;
			if (r != 0)
				num += rats[k].num_step - r;
		}
		diff = num - q * den;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.min = div_down(best_num, best_den);
	t.openmin = !!(best_num % best_den);
	
	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num;
		unsigned int den = rats[k].den;
		unsigned int q = i->max;
		int diff;
		num = mul(q, den);
		if (num < rats[k].num_min)
			continue;
		if (num > rats[k].num_max)
			num = rats[k].num_max;
		else {
			unsigned int r;
			r = (num - rats[k].num_min) % rats[k].num_step;
			if (r != 0)
				num -= r;
		}
		diff = q * den - num;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.max = div_up(best_num, best_den);
	t.openmax = !!(best_num % best_den);
	t.integer = 0;
	err = snd_interval_refine(i, &t);
	if (err < 0)
		return err;

	if (snd_interval_single(i)) {
		if (nump)
			*nump = best_num;
		if (denp)
			*denp = best_den;
	}
	return err;
}

Project: linux
File: pcm_lib.c

int snd_interval_ratnum(struct snd_interval *i,
			unsigned int rats_count, const struct snd_ratnum *rats,
			unsigned int *nump, unsigned int *denp)
{
	unsigned int best_num, best_den;
	int best_diff;
	unsigned int k;
	struct snd_interval t;
	int err;
	unsigned int result_num, result_den;
	int result_diff;

	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num = rats[k].num;
		unsigned int den;
		unsigned int q = i->min;
		int diff;
		if (q == 0)
			q = 1;
		den = div_up(num, q);
		if (den < rats[k].den_min)
			continue;
		if (den > rats[k].den_max)
			den = rats[k].den_max;
		else {
			unsigned int r;
			r = (den - rats[k].den_min) % rats[k].den_step;
			if (r != 0)
				den -= r;
		}
		diff = num - q * den;
		if (diff < 0)
			diff = -diff;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.min = div_down(best_num, best_den);
	t.openmin = !!(best_num % best_den);
	
	result_num = best_num;
	result_diff = best_diff;
	result_den = best_den;
	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num = rats[k].num;
		unsigned int den;
		unsigned int q = i->max;
		int diff;
		if (q == 0) {
			i->empty = 1;
			return -EINVAL;
		}
		den = div_down(num, q);
		if (den > rats[k].den_max)
			continue;
		if (den < rats[k].den_min)
			den = rats[k].den_min;
		else {
			unsigned int r;
			r = (den - rats[k].den_min) % rats[k].den_step;
			if (r != 0)
				den += rats[k].den_step - r;
		}
		diff = q * den - num;
		if (diff < 0)
			diff = -diff;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.max = div_up(best_num, best_den);
	t.openmax = !!(best_num % best_den);
	t.integer = 0;
	err = snd_interval_refine(i, &t);
	if (err < 0)
		return err;

	if (snd_interval_single(i)) {
		if (best_diff * result_den < result_diff * best_den) {
			result_num = best_num;
			result_den = best_den;
		}
		if (nump)
			*nump = result_num;
		if (denp)
			*denp = result_den;
	}
	return err;
}

Project: linux
File: pcm_lib.c

static int snd_interval_refine_first(struct snd_interval *i)
{
	if (snd_BUG_ON(snd_interval_empty(i)))
		return -EINVAL;
	if (snd_interval_single(i))
		return 0;
	i->max = i->min;
	i->openmax = i->openmin;
	if (i->openmax)
		i->max++;
	return 1;
}

Project: linux
File: pcm_lib.c

static int snd_interval_refine_last(struct snd_interval *i)
{
	if (snd_BUG_ON(snd_interval_empty(i)))
		return -EINVAL;
	if (snd_interval_single(i))
		return 0;
	i->min = i->max;
	i->openmin = i->openmax;
	if (i->openmin)
		i->min--;
	return 1;
}

Project: linux
File: pcm_lib.c

static int snd_interval_step(struct snd_interval *i, unsigned int step)
{
	unsigned int n;
	int changed = 0;
	n = i->min % step;
	if (n != 0 || i->openmin) {
		i->min += step - n;
		i->openmin = 0;
		changed = 1;
	}
	n = i->max % step;
	if (n != 0 || i->openmax) {
		i->max -= n;
		i->openmax = 0;
		changed = 1;
	}
	if (snd_interval_checkempty(i)) {
		i->empty = 1;
		return -EINVAL;
	}
	return changed;
}

Project: linux
File: pcm_lib.c

int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
			   const struct snd_pcm_chmap_elem *chmap,
			   int max_channels,
			   unsigned long private_value,
			   struct snd_pcm_chmap **info_ret)
{
	struct snd_pcm_chmap *info;
	struct snd_kcontrol_new knew = {
		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
		.access = SNDRV_CTL_ELEM_ACCESS_READ |
			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
		.info = pcm_chmap_ctl_info,
		.get = pcm_chmap_ctl_get,
		.tlv.c = pcm_chmap_ctl_tlv,
	};
	int err;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;
	info->pcm = pcm;
	info->stream = stream;
	info->chmap = chmap;
	info->max_channels = max_channels;
	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
		knew.name = "Playback Channel Map";
	else
		knew.name = "Capture Channel Map";
	knew.device = pcm->device;
	knew.count = pcm->streams[stream].substream_count;
	knew.private_value = private_value;
	info->kctl = snd_ctl_new1(&knew, info);
	if (!info->kctl) {
		kfree(info);
		return -ENOMEM;
	}
	info->kctl->private_free = pcm_chmap_ctl_private_free;
	err = snd_ctl_add(pcm->card, info->kctl);
	if (err < 0)
		return err;
	pcm->streams[stream].chmap_kctl = info->kctl;
	if (info_ret)
		*info_ret = info;
	return 0;
}

Project: linux
File: pcm_lib.c

void snd_pcm_debug_name(struct snd_pcm_substream *substream,
			   char *name, size_t len)
{
	snprintf(name, len, "pcmC%dD%d%c:%d",
		 substream->pcm->card->number,
		 substream->pcm->device,
		 substream->stream ? 'c' : 'p',
		 substream->number);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	return snd_interval_setinteger(constrs_interval(constrs, var));
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
			       unsigned int cond,
			       snd_pcm_hw_param_t var,
			       const struct snd_pcm_hw_constraint_list *l)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_list, (void *)l,
				   var, -1);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
			       u_int32_t mask)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_mask *maskp = constrs_mask(constrs, var);
	*maskp->bits &= mask;
	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
	if (*maskp->bits == 0)
		return -EINVAL;
	return 0;
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
				 u_int64_t mask)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_mask *maskp = constrs_mask(constrs, var);
	maskp->bits[0] &= (u_int32_t)mask;
	maskp->bits[1] &= (u_int32_t)(mask >> 32);
	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
	if (! maskp->bits[0] && ! maskp->bits[1])
		return -EINVAL;
	return 0;
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, 
				 unsigned int cond,
				 unsigned int width,
				 unsigned int msbits)
{
	unsigned long l = (msbits << 16) | width;
	return snd_pcm_hw_rule_add(runtime, cond, -1,
				    snd_pcm_hw_rule_msbits,
				    (void*) l,
				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
				 unsigned int cond,
				 snd_pcm_hw_param_t var,
				 const struct snd_pcm_hw_constraint_ranges *r)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_ranges, (void *)r,
				   var, -1);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, 
				  unsigned int cond,
				  snd_pcm_hw_param_t var,
				  const struct snd_pcm_hw_constraint_ratdens *r)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_ratdens, (void *)r,
				   var, -1);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, 
				  unsigned int cond,
				  snd_pcm_hw_param_t var,
				  const struct snd_pcm_hw_constraint_ratnums *r)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_ratnums, (void *)r,
				   var, -1);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, 
			   struct snd_pcm_hw_params *params, 
			   snd_pcm_hw_param_t var, int *dir)
{
	int changed = _snd_pcm_hw_param_first(params, var);
	if (changed < 0)
		return changed;
	if (params->rmask) {
		int err = snd_pcm_hw_refine(pcm, params);
		if (snd_BUG_ON(err < 0))
			return err;
	}
	return snd_pcm_hw_param_value(params, var, dir);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm, 
			  struct snd_pcm_hw_params *params,
			  snd_pcm_hw_param_t var, int *dir)
{
	int changed = _snd_pcm_hw_param_last(params, var);
	if (changed < 0)
		return changed;
	if (params->rmask) {
		int err = snd_pcm_hw_refine(pcm, params);
		if (snd_BUG_ON(err < 0))
			return err;
	}
	return snd_pcm_hw_param_value(params, var, dir);
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
			   snd_pcm_hw_param_t var, int *dir)
{
	if (hw_is_mask(var)) {
		const struct snd_mask *mask = hw_param_mask_c(params, var);
		if (!snd_mask_single(mask))
			return -EINVAL;
		if (dir)
			*dir = 0;
		return snd_mask_value(mask);
	}
	if (hw_is_interval(var)) {
		const struct snd_interval *i = hw_param_interval_c(params, var);
		if (!snd_interval_single(i))
			return -EINVAL;
		if (dir)
			*dir = i->openmin;
		return snd_interval_value(i);
	}
	return -EINVAL;
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
			     struct snd_pcm_hw_params *params)
{
	static int vars[] = {
		SNDRV_PCM_HW_PARAM_ACCESS,
		SNDRV_PCM_HW_PARAM_FORMAT,
		SNDRV_PCM_HW_PARAM_SUBFORMAT,
		SNDRV_PCM_HW_PARAM_CHANNELS,
		SNDRV_PCM_HW_PARAM_RATE,
		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
		SNDRV_PCM_HW_PARAM_TICK_TIME,
		-1
	};
	int err, *v;

	for (v = vars; *v != -1; v++) {
		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
		else
			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
		if (snd_BUG_ON(err < 0))
			return err;
	}
	return 0;
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
			int var,
			snd_pcm_hw_rule_func_t func, void *private,
			int dep, ...)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_pcm_hw_rule *c;
	unsigned int k;
	va_list args;
	va_start(args, dep);
	if (constrs->rules_num >= constrs->rules_all) {
		struct snd_pcm_hw_rule *new;
		unsigned int new_rules = constrs->rules_all + 16;
		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
		if (!new) {
			va_end(args);
			return -ENOMEM;
		}
		if (constrs->rules) {
			memcpy(new, constrs->rules,
			       constrs->rules_num * sizeof(*c));
			kfree(constrs->rules);
		}
		constrs->rules = new;
		constrs->rules_all = new_rules;
	}
	c = &constrs->rules[constrs->rules_num];
	c->cond = cond;
	c->func = func;
	c->var = var;
	c->private = private;
	k = 0;
	while (1) {
		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
			va_end(args);
			return -EINVAL;
		}
		c->deps[k++] = dep;
		if (dep < 0)
			break;
		dep = va_arg(args, int);
	}
	constrs->rules_num++;
	va_end(args);
	return 0;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	struct snd_pcm_hw_constraint_list *list = rule->private;
	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
				  struct snd_pcm_hw_rule *rule)
{
	unsigned int l = (unsigned long) rule->private;
	int width = l & 0xffff;
	unsigned int msbits = l >> 16;
	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);

	if (!snd_interval_single(i))
		return 0;

	if ((snd_interval_value(i) == width) ||
	    (width == 0 && snd_interval_value(i) > msbits))
		params->msbits = min_not_zero(params->msbits, msbits);

	return 0;
}

Project: linux
File: pcm_lib.c

int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
			       unsigned int base_rate)
{
	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
				   SNDRV_PCM_HW_PARAM_RATE,
				   snd_pcm_hw_rule_noresample_func,
				   (void *)(uintptr_t)base_rate,
				   SNDRV_PCM_HW_PARAM_RATE, -1);
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
					   struct snd_pcm_hw_rule *rule)
{
	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
	struct snd_interval *rate;

	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	return snd_interval_list(rate, 1, &base_rate, 0);
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
{
	static unsigned int pow2_sizes[] = {
		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
	};
	return snd_interval_list(hw_param_interval(params, rule->var),
				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
				  struct snd_pcm_hw_rule *rule)
{
	struct snd_pcm_hw_constraint_ranges *r = rule->private;
	return snd_interval_ranges(hw_param_interval(params, rule->var),
				   r->count, r->ranges, r->mask);
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
				   struct snd_pcm_hw_rule *rule)
{
	const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
	unsigned int num = 0, den = 0;
	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
				  r->nrats, r->rats, &num, &den);
	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
		params->rate_num = num;
		params->rate_den = den;
	}
	return err;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
				   struct snd_pcm_hw_rule *rule)
{
	const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
	unsigned int num = 0, den = 0;
	int err;
	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
				  r->nrats, r->rats, &num, &den);
	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
		params->rate_num = num;
		params->rate_den = den;
	}
	return err;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	unsigned long step = (unsigned long) rule->private;
	return snd_interval_step(hw_param_interval(params, rule->var), step);
}

Project: linux
File: pcm_lib.c

int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
		      unsigned int cmd, void *arg)
{
	switch (cmd) {
	case SNDRV_PCM_IOCTL1_INFO:
		return 0;
	case SNDRV_PCM_IOCTL1_RESET:
		return snd_pcm_lib_ioctl_reset(substream, arg);
	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
		return snd_pcm_lib_ioctl_channel_info(substream, arg);
	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
	}
	return -ENXIO;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
					  void *arg)
{
	struct snd_pcm_channel_info *info = arg;
	struct snd_pcm_runtime *runtime = substream->runtime;
	int width;
	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
		info->offset = -1;
		return 0;
	}
	width = snd_pcm_format_physical_width(runtime->format);
	if (width < 0)
		return width;
	info->offset = 0;
	switch (runtime->access) {
	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
		info->first = info->channel * width;
		info->step = runtime->channels * width;
		break;
	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
	{
		size_t size = runtime->dma_bytes / runtime->channels;
		info->first = info->channel * size * 8;
		info->step = width;
		break;
	}
	default:
		snd_BUG();
		break;
	}
	return 0;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
				       void *arg)
{
	struct snd_pcm_hw_params *params = arg;
	snd_pcm_format_t format;
	int channels;
	ssize_t frame_size;

	params->fifo_size = substream->runtime->hw.fifo_size;
	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
		format = params_format(params);
		channels = params_channels(params);
		frame_size = snd_pcm_format_size(format, channels);
		if (frame_size > 0)
			params->fifo_size /= (unsigned)frame_size;
	}
	return 0;
}

Project: linux
File: pcm_lib.c

snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
{
	struct snd_pcm_runtime *runtime;
	int nonblock;
	int err;
	
	err = pcm_sanity_check(substream);
	if (err < 0)
		return err;
	runtime = substream->runtime;
	nonblock = !!(substream->f_flags & O_NONBLOCK);
	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
		return -EINVAL;
	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
}

Project: linux
File: pcm_lib.c

static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
					   unsigned long data,
					   snd_pcm_uframes_t size,
					   int nonblock,
					   transfer_f transfer)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t xfer = 0;
	snd_pcm_uframes_t offset = 0;
	snd_pcm_uframes_t avail;
	int err = 0;

	if (size == 0)
		return 0;

	snd_pcm_stream_lock_irq(substream);
	switch (runtime->status->state) {
	case SNDRV_PCM_STATE_PREPARED:
		if (size >= runtime->start_threshold) {
			err = snd_pcm_start(substream);
			if (err < 0)
				goto _end_unlock;
		}
		break;
	case SNDRV_PCM_STATE_DRAINING:
	case SNDRV_PCM_STATE_RUNNING:
	case SNDRV_PCM_STATE_PAUSED:
		break;
	case SNDRV_PCM_STATE_XRUN:
		err = -EPIPE;
		goto _end_unlock;
	case SNDRV_PCM_STATE_SUSPENDED:
		err = -ESTRPIPE;
		goto _end_unlock;
	default:
		err = -EBADFD;
		goto _end_unlock;
	}

	runtime->twake = runtime->control->avail_min ? : 1;
	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
		snd_pcm_update_hw_ptr(substream);
	avail = snd_pcm_capture_avail(runtime);
	while (size > 0) {
		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
		snd_pcm_uframes_t cont;
		if (!avail) {
			if (runtime->status->state ==
			    SNDRV_PCM_STATE_DRAINING) {
				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
				goto _end_unlock;
			}
			if (nonblock) {
				err = -EAGAIN;
				goto _end_unlock;
			}
			runtime->twake = min_t(snd_pcm_uframes_t, size,
					runtime->control->avail_min ? : 1);
			err = wait_for_avail(substream, &avail);
			if (err < 0)
				goto _end_unlock;
			if (!avail)
				continue; /* draining */
		}
		frames = size > avail ? avail : size;
		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
		if (frames > cont)
			frames = cont;
		if (snd_BUG_ON(!frames)) {
			runtime->twake = 0;
			snd_pcm_stream_unlock_irq(substream);
			return -EINVAL;
		}
		appl_ptr = runtime->control->appl_ptr;
		appl_ofs = appl_ptr % runtime->buffer_size;
		snd_pcm_stream_unlock_irq(substream);
		err = transfer(substream, appl_ofs, data, offset, frames);
		snd_pcm_stream_lock_irq(substream);
		if (err < 0)
			goto _end_unlock;
		switch (runtime->status->state) {
		case SNDRV_PCM_STATE_XRUN:
			err = -EPIPE;
			goto _end_unlock;
		case SNDRV_PCM_STATE_SUSPENDED:
			err = -ESTRPIPE;
			goto _end_unlock;
		default:
			break;
		}
		appl_ptr += frames;
		if (appl_ptr >= runtime->boundary)
			appl_ptr -= runtime->boundary;
		runtime->control->appl_ptr = appl_ptr;
		if (substream->ops->ack)
			substream->ops->ack(substream);

		offset += frames;
		size -= frames;
		xfer += frames;
		avail -= frames;
	}
 _end_unlock:
	runtime->twake = 0;
	if (xfer > 0 && err >= 0)
		snd_pcm_update_state(substream, runtime);
	snd_pcm_stream_unlock_irq(substream);
	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream, 
				     unsigned int hwoff,
				     unsigned long data, unsigned int off,
				     snd_pcm_uframes_t frames)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
	if (substream->ops->copy) {
		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
			return err;
	} else {
		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
			return -EFAULT;
	}
	return 0;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
				      unsigned int hwoff,
				      unsigned long data, unsigned int off,
				      snd_pcm_uframes_t frames)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
	void __user **bufs = (void __user **)data;
	int channels = runtime->channels;
	int c;
	if (substream->ops->copy) {
		for (c = 0; c < channels; ++c, ++bufs) {
			char __user *buf;
			if (*bufs == NULL)
				continue;
			buf = *bufs + samples_to_bytes(runtime, off);
			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
				return err;
		}
	} else {
		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
		for (c = 0; c < channels; ++c, ++bufs) {
			char *hwbuf;
			char __user *buf;
			if (*bufs == NULL)
				continue;

			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
			buf = *bufs + samples_to_bytes(runtime, off);
			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
				return -EFAULT;
		}
	}
	return 0;
}

Project: linux
File: pcm_lib.c

snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
{
	struct snd_pcm_runtime *runtime;
	int nonblock;
	int err;

	err = pcm_sanity_check(substream);
	if (err < 0)
		return err;
	runtime = substream->runtime;
	nonblock = !!(substream->f_flags & O_NONBLOCK);

	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
	    runtime->channels > 1)
		return -EINVAL;
	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
				  snd_pcm_lib_write_transfer);
}

Project: linux
File: pcm_lib.c

static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream, 
					    unsigned long data,
					    snd_pcm_uframes_t size,
					    int nonblock,
					    transfer_f transfer)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t xfer = 0;
	snd_pcm_uframes_t offset = 0;
	snd_pcm_uframes_t avail;
	int err = 0;

	if (size == 0)
		return 0;

	snd_pcm_stream_lock_irq(substream);
	switch (runtime->status->state) {
	case SNDRV_PCM_STATE_PREPARED:
	case SNDRV_PCM_STATE_RUNNING:
	case SNDRV_PCM_STATE_PAUSED:
		break;
	case SNDRV_PCM_STATE_XRUN:
		err = -EPIPE;
		goto _end_unlock;
	case SNDRV_PCM_STATE_SUSPENDED:
		err = -ESTRPIPE;
		goto _end_unlock;
	default:
		err = -EBADFD;
		goto _end_unlock;
	}

	runtime->twake = runtime->control->avail_min ? : 1;
	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
		snd_pcm_update_hw_ptr(substream);
	avail = snd_pcm_playback_avail(runtime);
	while (size > 0) {
		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
		snd_pcm_uframes_t cont;
		if (!avail) {
			if (nonblock) {
				err = -EAGAIN;
				goto _end_unlock;
			}
			runtime->twake = min_t(snd_pcm_uframes_t, size,
					runtime->control->avail_min ? : 1);
			err = wait_for_avail(substream, &avail);
			if (err < 0)
				goto _end_unlock;
		}
		frames = size > avail ? avail : size;
		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
		if (frames > cont)
			frames = cont;
		if (snd_BUG_ON(!frames)) {
			runtime->twake = 0;
			snd_pcm_stream_unlock_irq(substream);
			return -EINVAL;
		}
		appl_ptr = runtime->control->appl_ptr;
		appl_ofs = appl_ptr % runtime->buffer_size;
		snd_pcm_stream_unlock_irq(substream);
		err = transfer(substream, appl_ofs, data, offset, frames);
		snd_pcm_stream_lock_irq(substream);
		if (err < 0)
			goto _end_unlock;
		switch (runtime->status->state) {
		case SNDRV_PCM_STATE_XRUN:
			err = -EPIPE;
			goto _end_unlock;
		case SNDRV_PCM_STATE_SUSPENDED:
			err = -ESTRPIPE;
			goto _end_unlock;
		default:
			break;
		}
		appl_ptr += frames;
		if (appl_ptr >= runtime->boundary)
			appl_ptr -= runtime->boundary;
		runtime->control->appl_ptr = appl_ptr;
		if (substream->ops->ack)
			substream->ops->ack(substream);

		offset += frames;
		size -= frames;
		xfer += frames;
		avail -= frames;
		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
			err = snd_pcm_start(substream);
			if (err < 0)
				goto _end_unlock;
		}
	}
 _end_unlock:
	runtime->twake = 0;
	if (xfer > 0 && err >= 0)
		snd_pcm_update_state(substream, runtime);
	snd_pcm_stream_unlock_irq(substream);
	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
				      unsigned int hwoff,
				      unsigned long data, unsigned int off,
				      snd_pcm_uframes_t frames)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
	if (substream->ops->copy) {
		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
			return err;
	} else {
		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
			return -EFAULT;
	}
	return 0;
}

Project: linux
File: pcm_lib.c

snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
				     void __user **bufs,
				     snd_pcm_uframes_t frames)
{
	struct snd_pcm_runtime *runtime;
	int nonblock;
	int err;

	err = pcm_sanity_check(substream);
	if (err < 0)
		return err;
	runtime = substream->runtime;
	nonblock = !!(substream->f_flags & O_NONBLOCK);

	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
		return -EINVAL;
	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
				  nonblock, snd_pcm_lib_writev_transfer);
}

Project: linux
File: pcm_lib.c

static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
				       unsigned int hwoff,
				       unsigned long data, unsigned int off,
				       snd_pcm_uframes_t frames)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
	void __user **bufs = (void __user **)data;
	int channels = runtime->channels;
	int c;
	if (substream->ops->copy) {
		if (snd_BUG_ON(!substream->ops->silence))
			return -EINVAL;
		for (c = 0; c < channels; ++c, ++bufs) {
			if (*bufs == NULL) {
				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
					return err;
			} else {
				char __user *buf = *bufs + samples_to_bytes(runtime, off);
				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
					return err;
			}
		}
	} else {
		/* default transfer behaviour */
		size_t dma_csize = runtime->dma_bytes / channels;
		for (c = 0; c < channels; ++c, ++bufs) {
			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
			if (*bufs == NULL) {
				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
			} else {
				char __user *buf = *bufs + samples_to_bytes(runtime, off);
				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
					return -EFAULT;
			}
		}
	}
	return 0;
}

Project: linux
File: pcm_lib.c

void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
		     const struct snd_pcm_ops *ops)
{
	struct snd_pcm_str *stream = &pcm->streams[direction];
	struct snd_pcm_substream *substream;
	
	for (substream = stream->substream; substream != NULL; substream = substream->next)
		substream->ops = ops;
}

Project: linux
File: pcm_lib.c

void snd_pcm_set_sync(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	
	runtime->sync.id32[0] = substream->pcm->card->number;
	runtime->sync.id32[1] = -1;
	runtime->sync.id32[2] = -1;
	runtime->sync.id32[3] = -1;
}

Project: linux
File: pcm_lib.c

static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
				  unsigned int in_interrupt)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t pos;
	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
	snd_pcm_sframes_t hdelta, delta;
	unsigned long jdelta;
	unsigned long curr_jiffies;
	struct timespec curr_tstamp;
	struct timespec audio_tstamp;
	int crossed_boundary = 0;

	old_hw_ptr = runtime->status->hw_ptr;

	/*
	 * group pointer, time and jiffies reads to allow for more
	 * accurate correlations/corrections.
	 * The values are stored at the end of this routine after
	 * corrections for hw_ptr position
	 */
	pos = substream->ops->pointer(substream);
	curr_jiffies = jiffies;
	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
		if ((substream->ops->get_time_info) &&
			(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
			substream->ops->get_time_info(substream, &curr_tstamp,
						&audio_tstamp,
						&runtime->audio_tstamp_config,
						&runtime->audio_tstamp_report);

			/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
			if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
				snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
		} else
			snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
	}

	if (pos == SNDRV_PCM_POS_XRUN) {
		xrun(substream);
		return -EPIPE;
	}
	if (pos >= runtime->buffer_size) {
		if (printk_ratelimit()) {
			char name[16];
			snd_pcm_debug_name(substream, name, sizeof(name));
			pcm_err(substream->pcm,
				"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
				name, pos, runtime->buffer_size,
				runtime->period_size);
		}
		pos = 0;
	}
	pos -= pos % runtime->min_align;
	trace_hwptr(substream, pos, in_interrupt);
	hw_base = runtime->hw_ptr_base;
	new_hw_ptr = hw_base + pos;
	if (in_interrupt) {
		/* we know that one period was processed */
		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
		delta = runtime->hw_ptr_interrupt + runtime->period_size;
		if (delta > new_hw_ptr) {
			/* check for double acknowledged interrupts */
			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
			if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
				hw_base += runtime->buffer_size;
				if (hw_base >= runtime->boundary) {
					hw_base = 0;
					crossed_boundary++;
				}
				new_hw_ptr = hw_base + pos;
				goto __delta;
			}
		}
	}
	/* new_hw_ptr might be lower than old_hw_ptr in case when */
	/* pointer crosses the end of the ring buffer */
	if (new_hw_ptr < old_hw_ptr) {
		hw_base += runtime->buffer_size;
		if (hw_base >= runtime->boundary) {
			hw_base = 0;
			crossed_boundary++;
		}
		new_hw_ptr = hw_base + pos;
	}
      __delta:
	delta = new_hw_ptr - old_hw_ptr;
	if (delta < 0)
		delta += runtime->boundary;

	if (runtime->no_period_wakeup) {
		snd_pcm_sframes_t xrun_threshold;
		/*
		 * Without regular period interrupts, we have to check
		 * the elapsed time to detect xruns.
		 */
		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
			goto no_delta_check;
		hdelta = jdelta - delta * HZ / runtime->rate;
		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
		while (hdelta > xrun_threshold) {
			delta += runtime->buffer_size;
			hw_base += runtime->buffer_size;
			if (hw_base >= runtime->boundary) {
				hw_base = 0;
				crossed_boundary++;
			}
			new_hw_ptr = hw_base + pos;
			hdelta -= runtime->hw_ptr_buffer_jiffies;
		}
		goto no_delta_check;
	}

	/* something must be really wrong */
	if (delta >= runtime->buffer_size + runtime->period_size) {
		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
			     substream->stream, (long)pos,
			     (long)new_hw_ptr, (long)old_hw_ptr);
		return 0;
	}

	/* Do jiffies check only in xrun_debug mode */
	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
		goto no_jiffies_check;

	/* Skip the jiffies check for hardwares with BATCH flag.
	 * Such hardware usually just increases the position at each IRQ,
	 * thus it can't give any strange position.
	 */
	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
		goto no_jiffies_check;
	hdelta = delta;
	if (hdelta < runtime->delay)
		goto no_jiffies_check;
	hdelta -= runtime->delay;
	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
		delta = jdelta /
			(((runtime->period_size * HZ) / runtime->rate)
								+ HZ/100);
		/* move new_hw_ptr according jiffies not pos variable */
		new_hw_ptr = old_hw_ptr;
		hw_base = delta;
		/* use loop to avoid checks for delta overflows */
		/* the delta value is small or zero in most cases */
		while (delta > 0) {
			new_hw_ptr += runtime->period_size;
			if (new_hw_ptr >= runtime->boundary) {
				new_hw_ptr -= runtime->boundary;
				crossed_boundary--;
			}
			delta--;
		}
		/* align hw_base to buffer_size */
		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
			     (long)pos, (long)hdelta,
			     (long)runtime->period_size, jdelta,
			     ((hdelta * HZ) / runtime->rate), hw_base,
			     (unsigned long)old_hw_ptr,
			     (unsigned long)new_hw_ptr);
		/* reset values to proper state */
		delta = 0;
		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
	}
 no_jiffies_check:
	if (delta > runtime->period_size + runtime->period_size / 2) {
		hw_ptr_error(substream, in_interrupt,
			     "Lost interrupts?",
			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
			     substream->stream, (long)delta,
			     (long)new_hw_ptr,
			     (long)old_hw_ptr);
	}

 no_delta_check:
	if (runtime->status->hw_ptr == new_hw_ptr) {
		update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
		return 0;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
	    runtime->silence_size > 0)
		snd_pcm_playback_silence(substream, new_hw_ptr);

	if (in_interrupt) {
		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
		if (delta < 0)
			delta += runtime->boundary;
		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
		runtime->hw_ptr_interrupt += delta;
		if (runtime->hw_ptr_interrupt >= runtime->boundary)
			runtime->hw_ptr_interrupt -= runtime->boundary;
	}
	runtime->hw_ptr_base = hw_base;
	runtime->status->hw_ptr = new_hw_ptr;
	runtime->hw_ptr_jiffies = curr_jiffies;
	if (crossed_boundary) {
		snd_BUG_ON(crossed_boundary != 1);
		runtime->hw_ptr_wrap += runtime->boundary;
	}

	update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);

	return snd_pcm_update_state(substream, runtime);
}

Project: linux
File: pcm_lib.c

static void update_audio_tstamp(struct snd_pcm_substream *substream,
				struct timespec *curr_tstamp,
				struct timespec *audio_tstamp)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	u64 audio_frames, audio_nsecs;
	struct timespec driver_tstamp;

	if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
		return;

	if (!(substream->ops->get_time_info) ||
		(runtime->audio_tstamp_report.actual_type ==
			SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {

		/*
		 * provide audio timestamp derived from pointer position
		 * add delay only if requested
		 */

		audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;

		if (runtime->audio_tstamp_config.report_delay) {
			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
				audio_frames -=  runtime->delay;
			else
				audio_frames +=  runtime->delay;
		}
		audio_nsecs = div_u64(audio_frames * 1000000000LL,
				runtime->rate);
		*audio_tstamp = ns_to_timespec(audio_nsecs);
	}
	runtime->status->audio_tstamp = *audio_tstamp;
	runtime->status->tstamp = *curr_tstamp;

	/*
	 * re-take a driver timestamp to let apps detect if the reference tstamp
	 * read by low-level hardware was provided with a delay
	 */
	snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
	runtime->driver_tstamp = driver_tstamp;
}

Project: linux
File: pcm_lib.c

static int wait_for_avail(struct snd_pcm_substream *substream,
			      snd_pcm_uframes_t *availp)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
	wait_queue_t wait;
	int err = 0;
	snd_pcm_uframes_t avail = 0;
	long wait_time, tout;

	init_waitqueue_entry(&wait, current);
	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&runtime->tsleep, &wait);

	if (runtime->no_period_wakeup)
		wait_time = MAX_SCHEDULE_TIMEOUT;
	else {
		wait_time = 10;
		if (runtime->rate) {
			long t = runtime->period_size * 2 / runtime->rate;
			wait_time = max(t, wait_time);
		}
		wait_time = msecs_to_jiffies(wait_time * 1000);
	}

	for (;;) {
		if (signal_pending(current)) {
			err = -ERESTARTSYS;
			break;
		}

		/*
		 * We need to check if space became available already
		 * (and thus the wakeup happened already) first to close
		 * the race of space already having become available.
		 * This check must happen after been added to the waitqueue
		 * and having current state be INTERRUPTIBLE.
		 */
		if (is_playback)
			avail = snd_pcm_playback_avail(runtime);
		else
			avail = snd_pcm_capture_avail(runtime);
		if (avail >= runtime->twake)
			break;
		snd_pcm_stream_unlock_irq(substream);

		tout = schedule_timeout(wait_time);

		snd_pcm_stream_lock_irq(substream);
		set_current_state(TASK_INTERRUPTIBLE);
		switch (runtime->status->state) {
		case SNDRV_PCM_STATE_SUSPENDED:
			err = -ESTRPIPE;
			goto _endloop;
		case SNDRV_PCM_STATE_XRUN:
			err = -EPIPE;
			goto _endloop;
		case SNDRV_PCM_STATE_DRAINING:
			if (is_playback)
				err = -EPIPE;
			else 
				avail = 0; /* indicate draining */
			goto _endloop;
		case SNDRV_PCM_STATE_OPEN:
		case SNDRV_PCM_STATE_SETUP:
		case SNDRV_PCM_STATE_DISCONNECTED:
			err = -EBADFD;
			goto _endloop;
		case SNDRV_PCM_STATE_PAUSED:
			continue;
		}
		if (!tout) {
			pcm_dbg(substream->pcm,
				"%s write error (DMA or IRQ trouble?)\n",
				is_playback ? "playback" : "capture");
			err = -EIO;
			break;
		}
	}
 _endloop:
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&runtime->tsleep, &wait);
	*availp = avail;
	return err;
}

Project: linux
File: pcm_lib.c

static void xrun(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	trace_xrun(substream);
	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
		char name[16];
		snd_pcm_debug_name(substream, name, sizeof(name));
		pcm_warn(substream->pcm, "XRUN: %s\n", name);
		dump_stack_on_xrun(substream);
	}
}