ALSA: compress: fix drain calls blocking other compress functions
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@intel.com>
CC: stable@vger.kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index 9031a26..175ab32 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -48,6 +48,8 @@
* 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 @@
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 @@
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
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index bea523a..3eb47d0 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -123,6 +123,7 @@
}
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 @@
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 @@
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 @@
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)
