[alsa-devel] [PATCH] ASoC: DaVinci: Update suspend/resume support for McASP driver

[Chaithrika U S]

On Wed, Dec 02, 2009 at 14:56:31, Takashi Iwai wrote:
> At Wed,  2 Dec 2009 12:39:00 +0530,
> Chaithrika U S wrote:
> > 
> > diff --git a/sound/soc/davinci/davinci-pcm.c b/sound/soc/davinci/davinci-pcm.c
> > index ad4d7f4..80c7fdf 100644
> > --- a/sound/soc/davinci/davinci-pcm.c
> > +++ b/sound/soc/davinci/davinci-pcm.c
> > @@ -49,7 +49,7 @@ static void print_buf_info(int slot, char *name)
> >  static struct snd_pcm_hardware pcm_hardware_playback = {
> >  	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
> >  		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
> > -		 SNDRV_PCM_INFO_PAUSE),
> > +		 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME),
> 
> Note that unless your driver supports the "full" resume,
> SNDRV_PCM_INFO_RESUME shouldn't be set.  Here, the "full" resume means
> that the hardware gets back to a completely sane state and the PCM
> streams are resumed without extra PCM prepare call at PM resume.
> If the PCM (or whatever) needs another re-initialization (like in many
> cases), don't set this flag.
> 
> Just to be sure...
> 
> 
> Takashi
> 

PCM prepare call is not needed in this case. Testing was done with audio
loopback and after a suspend/resume cycle the audio output was proper. Hope
my understanding is correct. Is this test sufficient to prove that driver
supports full resume?

Regards, 
Chaithrika