From: Jassi Brar <jassi.brar@xxxxxxxxxxx>
The check for at least 'avail_min' available data before calling wake_up
doesn't always hold good as it does not guarantee callbacks at each periodic
interrupt.
An example of such situation is snd_pcm_lib_read1/write1 consuming some space
of the period and going to sleep from wait_for_avail_min upon syncing with
the DMA pointer. Clearly just the remainder of period size is needed, but
wake_up is called only after _two_ periodic interrupts from that point.
Signed-off-by: Jassi Brar <jassi.brar@xxxxxxxxxxx>
---
sound/core/pcm_lib.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 30f4108..ee2d7b9 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -189,7 +189,7 @@ snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime)
{
- snd_pcm_uframes_t avail;
+ snd_pcm_uframes_t avail, prd_short;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
avail = snd_pcm_playback_avail(runtime);
@@ -208,8 +208,14 @@ static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
return -EPIPE;
}
}
- if (avail >= runtime->control->avail_min)
+
+ prd_short = runtime->period_size
+ - runtime->status->hw_ptr % runtime->period_size;
+
+ if (avail >= runtime->control->avail_min
+ || avail >= prd_short)
wake_up(&runtime->sleep);
+
return 0;
}
--
1.6.2.5
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