From 741b20cfb9109760937f403d18d731bfde31f56f Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Thu, 17 Dec 2009 17:34:39 +0100
Subject: ALSA: pcm_lib.c - convert second xrun_debug() parameter to use
 defines

To increase code readability, convert send xrun_debug() argument to
use defines.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/core/pcm_lib.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

(limited to 'sound/core')

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 30f410832a2..9621236b2fe 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -126,15 +126,22 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
 	}
 }
 
+#define XRUN_DEBUG_BASIC	(1<<0)
+#define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
+#define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
+#define XRUN_DEBUG_PERIODUPDATE	(1<<3)	/* full period update info */
+#define XRUN_DEBUG_HWPTRUPDATE	(1<<4)	/* full hwptr update info */
+
 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
-#define xrun_debug(substream, mask)	((substream)->pstr->xrun_debug & (mask))
+#define xrun_debug(substream, mask) \
+			((substream)->pstr->xrun_debug & (mask))
 #else
 #define xrun_debug(substream, mask)	0
 #endif
 
-#define dump_stack_on_xrun(substream) do {		\
-		if (xrun_debug(substream, 2))		\
-			dump_stack();			\
+#define dump_stack_on_xrun(substream) do {			\
+		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
+			dump_stack();				\
 	} while (0)
 
 static void pcm_debug_name(struct snd_pcm_substream *substream,
@@ -154,7 +161,7 @@ static void xrun(struct snd_pcm_substream *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, 1)) {
+	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
 		char name[16];
 		pcm_debug_name(substream, name, sizeof(name));
 		snd_printd(KERN_DEBUG "XRUN: %s\n", name);
@@ -215,7 +222,7 @@ static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
 
 #define hw_ptr_error(substream, fmt, args...)				\
 	do {								\
-		if (xrun_debug(substream, 1)) {				\
+		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
 			if (printk_ratelimit()) {			\
 				snd_printd("PCM: " fmt, ##args);	\
 			}						\
@@ -237,7 +244,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 		xrun(substream);
 		return -EPIPE;
 	}
-	if (xrun_debug(substream, 8)) {
+	if (xrun_debug(substream, XRUN_DEBUG_PERIODUPDATE)) {
 		char name[16];
 		pcm_debug_name(substream, name, sizeof(name));
 		snd_printd("period_update: %s: pos=0x%x/0x%x/0x%x, "
@@ -290,7 +297,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 	}
 
 	/* Do jiffies check only in xrun_debug mode */
-	if (!xrun_debug(substream, 4))
+	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 		goto no_jiffies_check;
 
 	/* Skip the jiffies check for hardwares with BATCH flag.
@@ -369,7 +376,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 		xrun(substream);
 		return -EPIPE;
 	}
-	if (xrun_debug(substream, 16)) {
+	if (xrun_debug(substream, XRUN_DEBUG_HWPTRUPDATE)) {
 		char name[16];
 		pcm_debug_name(substream, name, sizeof(name));
 		snd_printd("hw_update: %s: pos=0x%x/0x%x/0x%x, "
@@ -403,7 +410,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 		new_hw_ptr = hw_base + pos;
 	}
 	/* Do jiffies check only in xrun_debug mode */
-	if (!xrun_debug(substream, 4))
+	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 		goto no_jiffies_check;
 	if (delta < runtime->delay)
 		goto no_jiffies_check;
-- 
cgit v1.2.3


From 4d96eb255c53ab5e39b37fd4d484ea3dc39ab456 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Sun, 20 Dec 2009 11:47:57 +0100
Subject: ALSA: pcm_lib - add possibility to log last 10 DMA ring buffer
 positions

In some debug cases, it might be usefull to see previous ring buffer
positions to determine position problems from the lowlevel drivers.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/core/pcm.c     |   4 ++
 sound/core/pcm_lib.c | 140 ++++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 121 insertions(+), 23 deletions(-)

(limited to 'sound/core')

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 6884ae031f6..df57a0e30bf 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -921,6 +921,10 @@ void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 	snd_free_pages((void*)runtime->control,
 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
 	kfree(runtime->hw_constraints.rules);
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+	if (runtime->hwptr_log)
+		kfree(runtime->hwptr_log);
+#endif
 	kfree(runtime);
 	substream->runtime = NULL;
 	put_pid(substream->pid);
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 9621236b2fe..1990afb8a73 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -126,34 +126,34 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
 	}
 }
 
+static void 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);
+}
+
 #define XRUN_DEBUG_BASIC	(1<<0)
 #define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
 #define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
 #define XRUN_DEBUG_PERIODUPDATE	(1<<3)	/* full period update info */
 #define XRUN_DEBUG_HWPTRUPDATE	(1<<4)	/* full hwptr update info */
+#define XRUN_DEBUG_LOG		(1<<5)	/* show last 10 positions on err */
+#define XRUN_DEBUG_LOGONCE	(1<<6)	/* do above only once */
 
 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
+
 #define xrun_debug(substream, mask) \
 			((substream)->pstr->xrun_debug & (mask))
-#else
-#define xrun_debug(substream, mask)	0
-#endif
 
 #define dump_stack_on_xrun(substream) do {			\
 		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
 			dump_stack();				\
 	} while (0)
 
-static void 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);
-}
-
 static void xrun(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
@@ -169,6 +169,102 @@ static void xrun(struct snd_pcm_substream *substream)
 	}
 }
 
+#define hw_ptr_error(substream, fmt, args...)				\
+	do {								\
+		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
+			if (printk_ratelimit()) {			\
+				snd_printd("PCM: " fmt, ##args);	\
+			}						\
+			dump_stack_on_xrun(substream);			\
+		}							\
+	} while (0)
+
+#define XRUN_LOG_CNT	10
+
+struct hwptr_log_entry {
+	unsigned long jiffies;
+	snd_pcm_uframes_t pos;
+	snd_pcm_uframes_t period_size;
+	snd_pcm_uframes_t buffer_size;
+	snd_pcm_uframes_t old_hw_ptr;
+	snd_pcm_uframes_t hw_ptr_base;
+	snd_pcm_uframes_t hw_ptr_interrupt;
+};
+
+struct snd_pcm_hwptr_log {
+	unsigned int idx;
+	unsigned int hit: 1;
+	struct hwptr_log_entry entries[XRUN_LOG_CNT];
+};
+
+static void xrun_log(struct snd_pcm_substream *substream,
+		     snd_pcm_uframes_t pos)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_hwptr_log *log = runtime->hwptr_log;
+	struct hwptr_log_entry *entry;
+
+	if (log == NULL) {
+		log = kzalloc(sizeof(*log), GFP_ATOMIC);
+		if (log == NULL)
+			return;
+		runtime->hwptr_log = log;
+	} else {
+		if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
+			return;
+	}
+	entry = &log->entries[log->idx];
+	entry->jiffies = jiffies;
+	entry->pos = pos;
+	entry->period_size = runtime->period_size;
+	entry->buffer_size = runtime->buffer_size;;
+	entry->old_hw_ptr = runtime->status->hw_ptr;
+	entry->hw_ptr_base = runtime->hw_ptr_base;
+	entry->hw_ptr_interrupt = runtime->hw_ptr_interrupt;;
+	log->idx = (log->idx + 1) % XRUN_LOG_CNT;
+}
+
+static void xrun_log_show(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_hwptr_log *log = substream->runtime->hwptr_log;
+	struct hwptr_log_entry *entry;
+	char name[16];
+	unsigned int idx;
+	int cnt;
+
+	if (log == NULL)
+		return;
+	if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
+		return;
+	pcm_debug_name(substream, name, sizeof(name));
+	for (cnt = 0, idx = log->idx; cnt < XRUN_LOG_CNT; cnt++) {
+		entry = &log->entries[idx];
+		if (entry->period_size == 0)
+			break;
+		snd_printd("hwptr log: %s: j=%lu, pos=0x%lx/0x%lx/0x%lx, "
+			   "hwptr=0x%lx, hw_base=0x%lx, hw_intr=0x%lx\n",
+			   name, entry->jiffies, (unsigned long)entry->pos,
+			   (unsigned long)entry->period_size,
+			   (unsigned long)entry->buffer_size,
+			   (unsigned long)entry->old_hw_ptr,
+			   (unsigned long)entry->hw_ptr_base,
+			   (unsigned long)entry->hw_ptr_interrupt);
+		idx++;
+		idx %= XRUN_LOG_CNT;
+	}
+	log->hit = 1;
+}
+
+#else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
+
+#define xrun_debug(substream, mask)	0
+#define xrun(substream)			do { } while (0)
+#define hw_ptr_error(substream, fmt, args...) do { } while (0)
+#define xrun_log(substream, pos)	do { } while (0)
+#define xrun_log_show(substream)	do { } while (0)
+
+#endif
+
 static snd_pcm_uframes_t
 snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
 			  struct snd_pcm_runtime *runtime)
@@ -182,6 +278,7 @@ snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
 		if (printk_ratelimit()) {
 			char name[16];
 			pcm_debug_name(substream, name, sizeof(name));
+			xrun_log_show(substream);
 			snd_printd(KERN_ERR  "BUG: %s, pos = 0x%lx, "
 				   "buffer size = 0x%lx, period size = 0x%lx\n",
 				   name, pos, runtime->buffer_size,
@@ -190,6 +287,8 @@ snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
 		pos = 0;
 	}
 	pos -= pos % runtime->min_align;
+	if (xrun_debug(substream, XRUN_DEBUG_LOG))
+		xrun_log(substream, pos);
 	return pos;
 }
 
@@ -220,16 +319,6 @@ static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-#define hw_ptr_error(substream, fmt, args...)				\
-	do {								\
-		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
-			if (printk_ratelimit()) {			\
-				snd_printd("PCM: " fmt, ##args);	\
-			}						\
-			dump_stack_on_xrun(substream);			\
-		}							\
-	} while (0)
-
 static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
@@ -270,6 +359,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 		if (runtime->periods == 1 || new_hw_ptr < old_hw_ptr)
 			delta += runtime->buffer_size;
 		if (delta < 0) {
+			xrun_log_show(substream);
 			hw_ptr_error(substream, 
 				     "Unexpected hw_pointer value "
 				     "(stream=%i, pos=%ld, intr_ptr=%ld)\n",
@@ -315,6 +405,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 		delta = jdelta /
 			(((runtime->period_size * HZ) / runtime->rate)
 								+ HZ/100);
+		xrun_log_show(substream);
 		hw_ptr_error(substream,
 			     "hw_ptr skipping! [Q] "
 			     "(pos=%ld, delta=%ld, period=%ld, "
@@ -334,6 +425,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 	}
  no_jiffies_check:
 	if (delta > runtime->period_size + runtime->period_size / 2) {
+		xrun_log_show(substream);
 		hw_ptr_error(substream,
 			     "Lost interrupts? "
 			     "(stream=%i, delta=%ld, intr_ptr=%ld)\n",
@@ -397,6 +489,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 	if (delta < 0) {
 		delta += runtime->buffer_size;
 		if (delta < 0) {
+			xrun_log_show(substream);
 			hw_ptr_error(substream, 
 				     "Unexpected hw_pointer value [2] "
 				     "(stream=%i, pos=%ld, old_ptr=%ld, jdelta=%li)\n",
@@ -416,6 +509,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 		goto no_jiffies_check;
 	delta -= runtime->delay;
 	if (((delta * HZ) / runtime->rate) > jdelta + HZ/100) {
+		xrun_log_show(substream);
 		hw_ptr_error(substream,
 			     "hw_ptr skipping! "
 			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu)\n",
-- 
cgit v1.2.3


From f240406babfe1526998e10583ea5eccc2676a433 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Tue, 5 Jan 2010 17:19:34 +0100
Subject: ALSA: pcm_lib - cleanup & merge hw_ptr update functions

Do general cleanup in snd_pcm_update_hw_ptr*() routines and merge them.
The main change is hw_ptr_interrupt variable removal to simplify code
logic. This variable can be computed directly from hw_ptr.

Ensure that updated hw_ptr is not lower than previous one (it was possible
with old code in some obscure situations when interrupt was delayed or
the lowlevel driver returns wrong ring buffer position value).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/core/oss/pcm_oss.c |  32 ++++--
 sound/core/pcm_lib.c     | 279 ++++++++++++++++-------------------------------
 sound/core/pcm_native.c  |   2 -
 3 files changed, 120 insertions(+), 193 deletions(-)

(limited to 'sound/core')

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index d9c96353121..255ad910077 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -632,6 +632,13 @@ static long snd_pcm_alsa_frames(struct snd_pcm_substream *substream, long bytes)
 	return bytes_to_frames(runtime, (buffer_size * bytes) / runtime->oss.buffer_bytes);
 }
 
+static inline
+snd_pcm_uframes_t get_hw_ptr_period(struct snd_pcm_runtime *runtime)
+{
+	snd_pcm_uframes_t ptr = runtime->status->hw_ptr;
+	return ptr - (ptr % runtime->period_size);
+}
+
 /* define extended formats in the recent OSS versions (if any) */
 /* linear formats */
 #define AFMT_S32_LE      0x00001000
@@ -1102,7 +1109,7 @@ static int snd_pcm_oss_prepare(struct snd_pcm_substream *substream)
 		return err;
 	}
 	runtime->oss.prepare = 0;
-	runtime->oss.prev_hw_ptr_interrupt = 0;
+	runtime->oss.prev_hw_ptr_period = 0;
 	runtime->oss.period_ptr = 0;
 	runtime->oss.buffer_used = 0;
 
@@ -1950,7 +1957,8 @@ static int snd_pcm_oss_get_caps(struct snd_pcm_oss_file *pcm_oss_file)
 	return result;
 }
 
-static void snd_pcm_oss_simulate_fill(struct snd_pcm_substream *substream, snd_pcm_uframes_t hw_ptr)
+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;
@@ -1986,7 +1994,8 @@ static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int tr
 			if (runtime->oss.trigger)
 				goto _skip1;
 			if (atomic_read(&psubstream->mmap_count))
-				snd_pcm_oss_simulate_fill(psubstream, runtime->hw_ptr_interrupt);
+				snd_pcm_oss_simulate_fill(psubstream,
+						get_hw_ptr_period(runtime));
 			runtime->oss.trigger = 1;
 			runtime->start_threshold = 1;
 			cmd = SNDRV_PCM_IOCTL_START;
@@ -2105,11 +2114,12 @@ static int snd_pcm_oss_get_ptr(struct snd_pcm_oss_file *pcm_oss_file, int stream
 	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;
+		delay = get_hw_ptr_period(runtime);
+		n = delay - runtime->oss.prev_hw_ptr_period;
 		if (n < 0)
 			n += runtime->boundary;
 		info.blocks = n / runtime->period_size;
-		runtime->oss.prev_hw_ptr_interrupt = delay;
+		runtime->oss.prev_hw_ptr_period = 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;
@@ -2673,18 +2683,22 @@ 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;
+		return runtime->oss.prev_hw_ptr_period !=
+						get_hw_ptr_period(runtime);
 	else
-		return snd_pcm_playback_avail(runtime) >= runtime->oss.period_frames;
+		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;
+		return runtime->oss.prev_hw_ptr_period !=
+						get_hw_ptr_period(runtime);
 	else
-		return snd_pcm_capture_avail(runtime) >= runtime->oss.period_frames;
+		return snd_pcm_capture_avail(runtime) >=
+						runtime->oss.period_frames;
 }
 
 static unsigned int snd_pcm_oss_poll(struct file *file, poll_table * wait)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 1990afb8a73..70a4f7428d7 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -172,6 +172,7 @@ static void xrun(struct snd_pcm_substream *substream)
 #define hw_ptr_error(substream, fmt, args...)				\
 	do {								\
 		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
+			xrun_log_show(substream);			\
 			if (printk_ratelimit()) {			\
 				snd_printd("PCM: " fmt, ##args);	\
 			}						\
@@ -188,7 +189,6 @@ struct hwptr_log_entry {
 	snd_pcm_uframes_t buffer_size;
 	snd_pcm_uframes_t old_hw_ptr;
 	snd_pcm_uframes_t hw_ptr_base;
-	snd_pcm_uframes_t hw_ptr_interrupt;
 };
 
 struct snd_pcm_hwptr_log {
@@ -220,7 +220,6 @@ static void xrun_log(struct snd_pcm_substream *substream,
 	entry->buffer_size = runtime->buffer_size;;
 	entry->old_hw_ptr = runtime->status->hw_ptr;
 	entry->hw_ptr_base = runtime->hw_ptr_base;
-	entry->hw_ptr_interrupt = runtime->hw_ptr_interrupt;;
 	log->idx = (log->idx + 1) % XRUN_LOG_CNT;
 }
 
@@ -241,14 +240,13 @@ static void xrun_log_show(struct snd_pcm_substream *substream)
 		entry = &log->entries[idx];
 		if (entry->period_size == 0)
 			break;
-		snd_printd("hwptr log: %s: j=%lu, pos=0x%lx/0x%lx/0x%lx, "
-			   "hwptr=0x%lx, hw_base=0x%lx, hw_intr=0x%lx\n",
+		snd_printd("hwptr log: %s: j=%lu, pos=%ld/%ld/%ld, "
+			   "hwptr=%ld/%ld\n",
 			   name, entry->jiffies, (unsigned long)entry->pos,
 			   (unsigned long)entry->period_size,
 			   (unsigned long)entry->buffer_size,
 			   (unsigned long)entry->old_hw_ptr,
-			   (unsigned long)entry->hw_ptr_base,
-			   (unsigned long)entry->hw_ptr_interrupt);
+			   (unsigned long)entry->hw_ptr_base);
 		idx++;
 		idx %= XRUN_LOG_CNT;
 	}
@@ -265,33 +263,6 @@ static void xrun_log_show(struct snd_pcm_substream *substream)
 
 #endif
 
-static snd_pcm_uframes_t
-snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
-			  struct snd_pcm_runtime *runtime)
-{
-	snd_pcm_uframes_t pos;
-
-	pos = substream->ops->pointer(substream);
-	if (pos == SNDRV_PCM_POS_XRUN)
-		return pos; /* XRUN */
-	if (pos >= runtime->buffer_size) {
-		if (printk_ratelimit()) {
-			char name[16];
-			pcm_debug_name(substream, name, sizeof(name));
-			xrun_log_show(substream);
-			snd_printd(KERN_ERR  "BUG: %s, pos = 0x%lx, "
-				   "buffer size = 0x%lx, period size = 0x%lx\n",
-				   name, pos, runtime->buffer_size,
-				   runtime->period_size);
-		}
-		pos = 0;
-	}
-	pos -= pos % runtime->min_align;
-	if (xrun_debug(substream, XRUN_DEBUG_LOG))
-		xrun_log(substream, pos);
-	return pos;
-}
-
 static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
 				      struct snd_pcm_runtime *runtime)
 {
@@ -319,72 +290,88 @@ static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
+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_ptr_interrupt, hw_base;
+	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
 	snd_pcm_sframes_t hdelta, delta;
 	unsigned long jdelta;
 
 	old_hw_ptr = runtime->status->hw_ptr;
-	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
+	pos = substream->ops->pointer(substream);
 	if (pos == SNDRV_PCM_POS_XRUN) {
 		xrun(substream);
 		return -EPIPE;
 	}
-	if (xrun_debug(substream, XRUN_DEBUG_PERIODUPDATE)) {
-		char name[16];
-		pcm_debug_name(substream, name, sizeof(name));
-		snd_printd("period_update: %s: pos=0x%x/0x%x/0x%x, "
-			   "hwptr=0x%lx, hw_base=0x%lx, hw_intr=0x%lx\n",
-			   name, (unsigned int)pos,
-			   (unsigned int)runtime->period_size,
-			   (unsigned int)runtime->buffer_size,
-			   (unsigned long)old_hw_ptr,
-			   (unsigned long)runtime->hw_ptr_base,
-			   (unsigned long)runtime->hw_ptr_interrupt);
+	if (pos >= runtime->buffer_size) {
+		if (printk_ratelimit()) {
+			char name[16];
+			pcm_debug_name(substream, name, sizeof(name));
+			xrun_log_show(substream);
+			snd_printd(KERN_ERR  "BUG: %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;
+	if (xrun_debug(substream, XRUN_DEBUG_LOG))
+		xrun_log(substream, pos);
 	hw_base = runtime->hw_ptr_base;
 	new_hw_ptr = hw_base + pos;
-	hw_ptr_interrupt = runtime->hw_ptr_interrupt + runtime->period_size;
-	delta = new_hw_ptr - hw_ptr_interrupt;
-	if (hw_ptr_interrupt >= runtime->boundary) {
-		hw_ptr_interrupt -= runtime->boundary;
-		if (hw_base < runtime->boundary / 2)
-			/* hw_base was already lapped; recalc delta */
-			delta = new_hw_ptr - hw_ptr_interrupt;
-	}
-	if (delta < 0) {
-		if (runtime->periods == 1 || new_hw_ptr < old_hw_ptr)
-			delta += runtime->buffer_size;
-		if (delta < 0) {
-			xrun_log_show(substream);
-			hw_ptr_error(substream, 
-				     "Unexpected hw_pointer value "
-				     "(stream=%i, pos=%ld, intr_ptr=%ld)\n",
-				     substream->stream, (long)pos,
-				     (long)hw_ptr_interrupt);
-#if 1
-			/* simply skipping the hwptr update seems more
-			 * robust in some cases, e.g. on VMware with
-			 * inaccurate timer source
-			 */
-			return 0; /* skip this update */
-#else
-			/* rebase to interrupt position */
-			hw_base = new_hw_ptr = hw_ptr_interrupt;
-			/* align hw_base to buffer_size */
-			hw_base -= hw_base % runtime->buffer_size;
-			delta = 0;
-#endif
-		} else {
+	if (in_interrupt) {
+		/* we know that one period was processed */
+		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
+		delta = old_hw_ptr - (old_hw_ptr % runtime->period_size)
+			+ runtime->period_size;
+		if (delta > new_hw_ptr) {
 			hw_base += runtime->buffer_size;
 			if (hw_base >= runtime->boundary)
 				hw_base = 0;
 			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;
+		new_hw_ptr = hw_base + pos;
+	}
+      __delta:
+	delta = (new_hw_ptr - old_hw_ptr) % runtime->boundary;
+	if (xrun_debug(substream, in_interrupt ?
+			XRUN_DEBUG_PERIODUPDATE : XRUN_DEBUG_HWPTRUPDATE)) {
+		char name[16];
+		pcm_debug_name(substream, name, sizeof(name));
+		snd_printd("%s_update: %s: pos=%u/%u/%u, "
+			   "hwptr=%ld/%ld/%ld/%ld\n",
+			   in_interrupt ? "period" : "hwptr",
+			   name,
+			   (unsigned int)pos,
+			   (unsigned int)runtime->period_size,
+			   (unsigned int)runtime->buffer_size,
+			   (unsigned long)delta,
+			   (unsigned long)old_hw_ptr,
+			   (unsigned long)new_hw_ptr,
+			   (unsigned long)runtime->hw_ptr_base);
+	}
+	/* something must be really wrong */
+	if (delta >= runtime->buffer_size) {
+		hw_ptr_error(substream,
+			       "Unexpected hw_pointer value %s"
+			       "(stream=%i, pos=%ld, new_hw_ptr=%ld, "
+			       "old_hw_ptr=%ld)\n",
+				     in_interrupt ? "[Q] " : "[P]",
+				     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))
@@ -396,7 +383,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 	 */
 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 		goto no_jiffies_check;
-	hdelta = new_hw_ptr - old_hw_ptr;
+	hdelta = delta;
 	if (hdelta < runtime->delay)
 		goto no_jiffies_check;
 	hdelta -= runtime->delay;
@@ -405,45 +392,49 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 		delta = jdelta /
 			(((runtime->period_size * HZ) / runtime->rate)
 								+ HZ/100);
-		xrun_log_show(substream);
+		/* move new_hw_ptr according jiffies not pos variable */
+		new_hw_ptr = old_hw_ptr;
+		/* 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;
+			delta--;
+		}
+		/* align hw_base to buffer_size */
+		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
+		delta = 0;
 		hw_ptr_error(substream,
-			     "hw_ptr skipping! [Q] "
+			     "hw_ptr skipping! %s"
 			     "(pos=%ld, delta=%ld, period=%ld, "
-			     "jdelta=%lu/%lu/%lu)\n",
+			     "jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
+			     in_interrupt ? "[Q] " : "",
 			     (long)pos, (long)hdelta,
 			     (long)runtime->period_size, jdelta,
-			     ((hdelta * HZ) / runtime->rate), delta);
-		hw_ptr_interrupt = runtime->hw_ptr_interrupt +
-				   runtime->period_size * delta;
-		if (hw_ptr_interrupt >= runtime->boundary)
-			hw_ptr_interrupt -= runtime->boundary;
-		/* rebase to interrupt position */
-		hw_base = new_hw_ptr = hw_ptr_interrupt;
-		/* align hw_base to buffer_size */
-		hw_base -= hw_base % runtime->buffer_size;
-		delta = 0;
+			     ((hdelta * HZ) / runtime->rate), delta,
+			     (unsigned long)old_hw_ptr,
+			     (unsigned long)new_hw_ptr);
 	}
  no_jiffies_check:
 	if (delta > runtime->period_size + runtime->period_size / 2) {
-		xrun_log_show(substream);
 		hw_ptr_error(substream,
-			     "Lost interrupts? "
-			     "(stream=%i, delta=%ld, intr_ptr=%ld)\n",
+			     "Lost interrupts? %s"
+			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, "
+			     "old_hw_ptr=%ld)\n",
+			     in_interrupt ? "[Q] " : "",
 			     substream->stream, (long)delta,
-			     (long)hw_ptr_interrupt);
-		/* rebase hw_ptr_interrupt */
-		hw_ptr_interrupt =
-			new_hw_ptr - new_hw_ptr % runtime->period_size;
+			     (long)new_hw_ptr,
+			     (long)old_hw_ptr);
 	}
-	runtime->hw_ptr_interrupt = hw_ptr_interrupt;
+
+	if (runtime->status->hw_ptr == new_hw_ptr)
+		return 0;
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 	    runtime->silence_size > 0)
 		snd_pcm_playback_silence(substream, new_hw_ptr);
 
-	if (runtime->status->hw_ptr == new_hw_ptr)
-		return 0;
-
 	runtime->hw_ptr_base = hw_base;
 	runtime->status->hw_ptr = new_hw_ptr;
 	runtime->hw_ptr_jiffies = jiffies;
@@ -456,83 +447,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
 /* CAUTION: call it with irq disabled */
 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 {
-	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 delta;
-	unsigned long jdelta;
-
-	old_hw_ptr = runtime->status->hw_ptr;
-	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
-	if (pos == SNDRV_PCM_POS_XRUN) {
-		xrun(substream);
-		return -EPIPE;
-	}
-	if (xrun_debug(substream, XRUN_DEBUG_HWPTRUPDATE)) {
-		char name[16];
-		pcm_debug_name(substream, name, sizeof(name));
-		snd_printd("hw_update: %s: pos=0x%x/0x%x/0x%x, "
-			   "hwptr=0x%lx, hw_base=0x%lx, hw_intr=0x%lx\n",
-			   name, (unsigned int)pos,
-			   (unsigned int)runtime->period_size,
-			   (unsigned int)runtime->buffer_size,
-			   (unsigned long)old_hw_ptr,
-			   (unsigned long)runtime->hw_ptr_base,
-			   (unsigned long)runtime->hw_ptr_interrupt);
-	}
-
-	hw_base = runtime->hw_ptr_base;
-	new_hw_ptr = hw_base + pos;
-
-	delta = new_hw_ptr - old_hw_ptr;
-	jdelta = jiffies - runtime->hw_ptr_jiffies;
-	if (delta < 0) {
-		delta += runtime->buffer_size;
-		if (delta < 0) {
-			xrun_log_show(substream);
-			hw_ptr_error(substream, 
-				     "Unexpected hw_pointer value [2] "
-				     "(stream=%i, pos=%ld, old_ptr=%ld, jdelta=%li)\n",
-				     substream->stream, (long)pos,
-				     (long)old_hw_ptr, jdelta);
-			return 0;
-		}
-		hw_base += runtime->buffer_size;
-		if (hw_base >= runtime->boundary)
-			hw_base = 0;
-		new_hw_ptr = hw_base + pos;
-	}
-	/* Do jiffies check only in xrun_debug mode */
-	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
-		goto no_jiffies_check;
-	if (delta < runtime->delay)
-		goto no_jiffies_check;
-	delta -= runtime->delay;
-	if (((delta * HZ) / runtime->rate) > jdelta + HZ/100) {
-		xrun_log_show(substream);
-		hw_ptr_error(substream,
-			     "hw_ptr skipping! "
-			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu)\n",
-			     (long)pos, (long)delta,
-			     (long)runtime->period_size, jdelta,
-			     ((delta * HZ) / runtime->rate));
-		return 0;
-	}
- no_jiffies_check:
-	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
-	    runtime->silence_size > 0)
-		snd_pcm_playback_silence(substream, new_hw_ptr);
-
-	if (runtime->status->hw_ptr == new_hw_ptr)
-		return 0;
-
-	runtime->hw_ptr_base = hw_base;
-	runtime->status->hw_ptr = new_hw_ptr;
-	runtime->hw_ptr_jiffies = jiffies;
-	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
-		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
-
-	return snd_pcm_update_hw_ptr_post(substream, runtime);
+	return snd_pcm_update_hw_ptr0(substream, 0);
 }
 
 /**
@@ -1744,7 +1659,7 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
 
 	snd_pcm_stream_lock_irqsave(substream, flags);
 	if (!snd_pcm_running(substream) ||
-	    snd_pcm_update_hw_ptr_interrupt(substream) < 0)
+	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
 		goto _end;
 
 	if (substream->timer_running)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 29ab46a12e1..8e777f71717 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1247,8 +1247,6 @@ static int snd_pcm_do_reset(struct snd_pcm_substream *substream, int state)
 	if (err < 0)
 		return err;
 	runtime->hw_ptr_base = 0;
-	runtime->hw_ptr_interrupt = runtime->status->hw_ptr -
-		runtime->status->hw_ptr % runtime->period_size;
 	runtime->silence_start = runtime->status->hw_ptr;
 	runtime->silence_filled = 0;
 	return 0;
-- 
cgit v1.2.3


From 1250932e48d3b698415b1f04775433cf1da688d6 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Thu, 7 Jan 2010 15:36:31 +0100
Subject: ALSA: pcm_lib - optimize wake_up() calls for PCM I/O

As noted by pl bossart <bossart.nospam@gmail.com>, the PCM I/O routines
(snd_pcm_lib_write1, snd_pcm_lib_read1) should block wake_up() calls
until all samples are not processed.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/core/pcm_lib.c    | 30 ++++++++++++++++++++----------
 sound/core/pcm_native.c |  6 ++++--
 2 files changed, 24 insertions(+), 12 deletions(-)

(limited to 'sound/core')

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 70a4f7428d7..a63226232ef 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -263,8 +263,8 @@ static void xrun_log_show(struct snd_pcm_substream *substream)
 
 #endif
 
-static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
-				      struct snd_pcm_runtime *runtime)
+int snd_pcm_update_state(struct snd_pcm_substream *substream,
+			 struct snd_pcm_runtime *runtime)
 {
 	snd_pcm_uframes_t avail;
 
@@ -285,7 +285,7 @@ static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
 			return -EPIPE;
 		}
 	}
-	if (avail >= runtime->control->avail_min)
+	if (!runtime->nowake && avail >= runtime->control->avail_min)
 		wake_up(&runtime->sleep);
 	return 0;
 }
@@ -441,7 +441,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
 
-	return snd_pcm_update_hw_ptr_post(substream, runtime);
+	return snd_pcm_update_state(substream, runtime);
 }
 
 /* CAUTION: call it with irq disabled */
@@ -1792,6 +1792,7 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
 		goto _end_unlock;
 	}
 
+	runtime->nowake = 1;
 	while (size > 0) {
 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
 		snd_pcm_uframes_t avail;
@@ -1813,15 +1814,17 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
 		if (frames > cont)
 			frames = cont;
 		if (snd_BUG_ON(!frames)) {
+			runtime->nowake = 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);
-		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
-			goto _end;
+		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;
@@ -1850,8 +1853,10 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
 		}
 	}
  _end_unlock:
+	runtime->nowake = 0;
+	if (xfer > 0 && err >= 0)
+		snd_pcm_update_state(substream, runtime);
 	snd_pcm_stream_unlock_irq(substream);
- _end:
 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
 }
 
@@ -2009,6 +2014,7 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
 		goto _end_unlock;
 	}
 
+	runtime->nowake = 1;
 	while (size > 0) {
 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
 		snd_pcm_uframes_t avail;
@@ -2037,15 +2043,17 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
 		if (frames > cont)
 			frames = cont;
 		if (snd_BUG_ON(!frames)) {
+			runtime->nowake = 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);
-		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
-			goto _end;
+		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;
@@ -2068,8 +2076,10 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
 		xfer += frames;
 	}
  _end_unlock:
+	runtime->nowake = 0;
+	if (xfer > 0 && err >= 0)
+		snd_pcm_update_state(substream, runtime);
 	snd_pcm_stream_unlock_irq(substream);
- _end:
 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
 }
 
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 8e777f71717..27284f62836 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -516,6 +516,7 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
 			     struct snd_pcm_sw_params *params)
 {
 	struct snd_pcm_runtime *runtime;
+	int err;
 
 	if (PCM_RUNTIME_CHECK(substream))
 		return -ENXIO;
@@ -540,6 +541,7 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
 		if (params->silence_threshold > runtime->buffer_size)
 			return -EINVAL;
 	}
+	err = 0;
 	snd_pcm_stream_lock_irq(substream);
 	runtime->tstamp_mode = params->tstamp_mode;
 	runtime->period_step = params->period_step;
@@ -553,10 +555,10 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 		    runtime->silence_size > 0)
 			snd_pcm_playback_silence(substream, ULONG_MAX);
-		wake_up(&runtime->sleep);
+		err = snd_pcm_update_state(substream, runtime);
 	}
 	snd_pcm_stream_unlock_irq(substream);
-	return 0;
+	return err;
 }
 
 static int snd_pcm_sw_params_user(struct snd_pcm_substream *substream,
-- 
cgit v1.2.3


From 7b3a177b0d4f92b3431b8dca777313a07533a710 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Fri, 8 Jan 2010 08:43:01 +0100
Subject: ALSA: pcm_lib: fix "something must be really wrong" condition

When runtime->periods == 1 or when pointer crosses end of ring buffer,
the delta might be greater than buffer_size.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/core/pcm_lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'sound/core')

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index a63226232ef..c7b35b20e65 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -362,7 +362,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 			   (unsigned long)runtime->hw_ptr_base);
 	}
 	/* something must be really wrong */
-	if (delta >= runtime->buffer_size) {
+	if (delta >= runtime->buffer_size + runtime->period_size) {
 		hw_ptr_error(substream,
 			       "Unexpected hw_pointer value %s"
 			       "(stream=%i, pos=%ld, new_hw_ptr=%ld, "
-- 
cgit v1.2.3