This is a note to let you know that I've just added the patch titled
ALSA: compress: fix drain calls blocking other compress functions (v6)
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-compress-fix-drain-calls-blocking-other-compress-functions-v6.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f44f2a5417b2968a8724b352cc0b2545a6bcb1f4 Mon Sep 17 00:00:00 2001
From: Vinod Koul <vinod.koul@xxxxxxxxx>
Date: Thu, 7 Nov 2013 10:08:22 +0100
Subject: ALSA: compress: fix drain calls blocking other compress functions (v6)
From: Vinod Koul <vinod.koul@xxxxxxxxx>
commit f44f2a5417b2968a8724b352cc0b2545a6bcb1f4 upstream.
The drain and drain_notify callback were blocked by low level driver
until the draining was complete. Due to this being invoked with big
fat mutex held, others ops like reading timestamp, calling pause, drop
were blocked.
So to fix this we add a new snd_compr_drain_notify() API. This would
be required to be invoked by low level driver when drain or partial
drain has been completed by the DSP. Thus we make the drain and
partial_drain callback as non blocking and driver returns immediately
after notifying DSP. The waiting is done while releasing the lock so
that other ops can go ahead.
[ The commit 917f4b5cba78 was wrongly applied from the preliminary
patch. This commit corrects to the final version.
Sorry for inconvenience! -- tiwai ]
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/sound/compress_driver.h | 11 ++++-------
sound/core/compress_offload.c | 31 +++++++++++++++++++------------
2 files changed, 23 insertions(+), 19 deletions(-)
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -48,8 +48,6 @@ struct snd_compr_ops;
* the ring buffer
* @total_bytes_transferred: cumulative bytes transferred by offload DSP
* @sleep: poll sleep
- * @wait: drain wait queue
- * @drain_wake: condition for drain wake
*/
struct snd_compr_runtime {
snd_pcm_state_t state;
@@ -61,8 +59,6 @@ struct snd_compr_runtime {
u64 total_bytes_available;
u64 total_bytes_transferred;
wait_queue_head_t sleep;
- wait_queue_head_t wait;
- unsigned int drain_wake;
void *private_data;
};
@@ -177,10 +173,11 @@ static inline void snd_compr_fragment_el
static inline void snd_compr_drain_notify(struct snd_compr_stream *stream)
{
- snd_BUG_ON(!stream);
+ if (snd_BUG_ON(!stream))
+ return;
- stream->runtime->drain_wake = 1;
- wake_up(&stream->runtime->wait);
+ stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+ wake_up(&stream->runtime->sleep);
}
#endif
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -123,7 +123,6 @@ static int snd_compr_open(struct inode *
}
runtime->state = SNDRV_PCM_STATE_OPEN;
init_waitqueue_head(&runtime->sleep);
- init_waitqueue_head(&runtime->wait);
data->stream.runtime = runtime;
f->private_data = (void *)data;
mutex_lock(&compr->lock);
@@ -681,8 +680,6 @@ static int snd_compr_stop(struct snd_com
return -EPERM;
retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
if (!retval) {
- stream->runtime->state = SNDRV_PCM_STATE_SETUP;
- wake_up(&stream->runtime->sleep);
snd_compr_drain_notify(stream);
stream->runtime->total_bytes_available = 0;
stream->runtime->total_bytes_transferred = 0;
@@ -692,6 +689,8 @@ static int snd_compr_stop(struct snd_com
static int snd_compress_wait_for_drain(struct snd_compr_stream *stream)
{
+ int ret;
+
/*
* We are called with lock held. So drop the lock while we wait for
* drain complete notfication from the driver
@@ -703,12 +702,24 @@ static int snd_compress_wait_for_drain(s
stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
mutex_unlock(&stream->device->lock);
- wait_event(stream->runtime->wait, stream->runtime->drain_wake);
+ /* we wait for drain to complete here, drain can return when
+ * interruption occurred, wait returned error or success.
+ * For the first two cases we don't do anything different here and
+ * return after waking up
+ */
+
+ ret = wait_event_interruptible(stream->runtime->sleep,
+ (stream->runtime->state != SNDRV_PCM_STATE_DRAINING));
+ if (ret == -ERESTARTSYS)
+ pr_debug("wait aborted by a signal");
+ else if (ret)
+ pr_debug("wait for drain failed with %d\n", ret);
+
wake_up(&stream->runtime->sleep);
mutex_lock(&stream->device->lock);
- return 0;
+ return ret;
}
static int snd_compr_drain(struct snd_compr_stream *stream)
@@ -719,17 +730,14 @@ static int snd_compr_drain(struct snd_co
stream->runtime->state == SNDRV_PCM_STATE_SETUP)
return -EPERM;
- stream->runtime->drain_wake = 0;
retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
if (retval) {
- pr_err("SND_COMPR_TRIGGER_DRAIN failed %d\n", retval);
+ pr_debug("SND_COMPR_TRIGGER_DRAIN failed %d\n", retval);
wake_up(&stream->runtime->sleep);
return retval;
}
- retval = snd_compress_wait_for_drain(stream);
- stream->runtime->state = SNDRV_PCM_STATE_SETUP;
- return retval;
+ return snd_compress_wait_for_drain(stream);
}
static int snd_compr_next_track(struct snd_compr_stream *stream)
@@ -764,10 +772,9 @@ static int snd_compr_partial_drain(struc
if (stream->next_track == false)
return -EPERM;
- stream->runtime->drain_wake = 0;
retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
if (retval) {
- pr_err("Partial drain returned failure\n");
+ pr_debug("Partial drain returned failure\n");
wake_up(&stream->runtime->sleep);
return retval;
}
Patches currently in stable-queue which might be from vinod.koul@xxxxxxxxx are
queue-3.12/alsa-compress-fix-drain-calls-blocking-other-compress-functions.patch
queue-3.12/alsa-compress-fix-drain-calls-blocking-other-compress-functions-v6.patch
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