ASoC: samsung dma - Don't indicate support for pause/resume.
authorDylan Reid <dgreid@chromium.org>
Sat, 1 Sep 2012 08:38:19 +0000 (01:38 -0700)
committerBen Hutchings <ben@decadent.org.uk>
Wed, 10 Oct 2012 02:30:44 +0000 (03:30 +0100)
commit62ed89fa28e6ecff1e4e9fb9664276d02862a2bc
treea58b58a343f08398851b53a220a6b613a9f40a26
parent288a2e6e152fde8349fe509cb7b5977a4f87edda
ASoC: samsung dma - Don't indicate support for pause/resume.

commit 57b2d68863f281737d8596cb3d76d89d9cc54fd8 upstream.

The pause and resume operations indicate that the stream can be
un-paused/resumed from the exact location they were paused/suspended.
This is not true for this driver, the pause and suspend triggers share
the same code path with stop, they flush all pending DMA transfers.
This drops all pending samples.  The pause_release/resume triggers are
the same as start, except that prepare won't be called beforehand,
nothing will be enqueued to the DMA engine and nothing will happen (no
audio).  Removing the pause flag will let apps know that it isn't
supported.  Removing the resume flag will cause user space to call
prepare and start instead of resume, so audio will continue playing when
the system wakes up.

Before removing the pause and resume flags, I tested this on an exynos
5250, using 'aplay -i'. Pause/un-pause leads to silence followed by a
write error.  Suspend/resume testing led to the same result.  Removing
the two flags fixes suspend/resume (since snd_pcm_prepare is called
again). And leads to a proper reporting of pause not supported.

Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sound/soc/samsung/dma.c