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
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.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 917f4b5cba78980a527098a910d94139d3e82c8d Mon Sep 17 00:00:00 2001
From: Vinod Koul <vinod.koul@xxxxxxxxx>
Date: Thu, 24 Oct 2013 16:37:31 +0530
Subject: ALSA: compress: fix drain calls blocking other compress functions
From: Vinod Koul <vinod.koul@xxxxxxxxx>
commit 917f4b5cba78980a527098a910d94139d3e82c8d upstream.
The drain and drain_notify callback were blocked by low level driver untill 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 relasing the lock so that other ops can go ahead.
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 | 12 +++++++++++
sound/core/compress_offload.c | 41 +++++++++++++++++++++++++++++++++++++---
2 files changed, 50 insertions(+), 3 deletions(-)
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -48,6 +48,8 @@ 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;
@@ -59,6 +61,8 @@ 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;
};
@@ -171,4 +175,12 @@ static inline void snd_compr_fragment_el
wake_up(&stream->runtime->sleep);
}
+static inline void snd_compr_drain_notify(struct snd_compr_stream *stream)
+{
+ snd_BUG_ON(!stream);
+
+ stream->runtime->drain_wake = 1;
+ wake_up(&stream->runtime->wait);
+}
+
#endif
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -123,6 +123,7 @@ 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);
@@ -682,12 +683,34 @@ static int snd_compr_stop(struct snd_com
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;
}
return retval;
}
+static int snd_compress_wait_for_drain(struct snd_compr_stream *stream)
+{
+ /*
+ * We are called with lock held. So drop the lock while we wait for
+ * drain complete notfication from the driver
+ *
+ * It is expected that driver will notify the drain completion and then
+ * stream will be moved to SETUP state, even if draining resulted in an
+ * error. We can trigger next track after this.
+ */
+ stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
+ mutex_unlock(&stream->device->lock);
+
+ wait_event(stream->runtime->wait, stream->runtime->drain_wake);
+
+ wake_up(&stream->runtime->sleep);
+ mutex_lock(&stream->device->lock);
+
+ return 0;
+}
+
static int snd_compr_drain(struct snd_compr_stream *stream)
{
int retval;
@@ -695,11 +718,17 @@ static int snd_compr_drain(struct snd_co
if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
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) {
- stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
+ if (retval) {
+ pr_err("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;
}
@@ -735,10 +764,16 @@ 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");
+ wake_up(&stream->runtime->sleep);
+ return retval;
+ }
stream->next_track = false;
- return retval;
+ return snd_compress_wait_for_drain(stream);
}
static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
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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