[PATCH 2/2] ASoC: OMAP: reconfigure DMA to resume audio

[PATCH 2/2] ASoC: OMAP: reconfigure DMA to resume audio

[Jane Wang]

Reconfigure DMA transfer parameters to resume audio after system comming out of OFF state.

Signed-off-by: Jane Wang <jwang@ti.com>
---
 sound/soc/omap/omap-pcm.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
index 6a829ee..5e04390 100644
--- a/sound/soc/omap/omap-pcm.c
+++ b/sound/soc/omap/omap-pcm.c
@@ -215,8 +215,13 @@ static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 
 	spin_lock_irqsave(&prtd->lock, flags);
 	switch (cmd) {
-	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
+		/* Reconfigure DMA transfer parameters
+		 * in order to come back from OFF mode
+		 */
+		omap_pcm_prepare(substream);
+		/* fall through */
+	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		prtd->period_index = 0;
 		/* Configure McBSP internal buffer usage */
-- 
1.5.4.3

Re: [PATCH 2/2] ASoC: OMAP: reconfigure DMA to resume audio

[Jarkko Nikula]

Hi

On Fri, 13 Nov 2009 12:02:03 -0600
Jane Wang <jwang@ti.com> wrote:

> Reconfigure DMA transfer parameters to resume audio after system comming out of OFF state.
> 
> Signed-off-by: Jane Wang <jwang@ti.com>
> ---
>  sound/soc/omap/omap-pcm.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
> index 6a829ee..5e04390 100644
> --- a/sound/soc/omap/omap-pcm.c
> +++ b/sound/soc/omap/omap-pcm.c
> @@ -215,8 +215,13 @@ static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
>  
>  	spin_lock_irqsave(&prtd->lock, flags);
>  	switch (cmd) {
> -	case SNDRV_PCM_TRIGGER_START:
>  	case SNDRV_PCM_TRIGGER_RESUME:
> +		/* Reconfigure DMA transfer parameters
> +		 * in order to come back from OFF mode
> +		 */
> +		omap_pcm_prepare(substream);
> +		/* fall through */

Again looks simple workaround for the audio case for restoring the
DMA context but how about all other DMA clients if the low-level DMA
module expects that the clients must do the context restore?

I'm not the PM expert but I think only need for PM in omap-pcm.c or
omap-mcbsp.c would be to dealing with possible suspend/resume order not
to bring up the low-level module back alive.


-- 
Jarkko

Re: [PATCH 2/2] ASoC: OMAP: reconfigure DMA to resume audio

[Mark Brown]

On Thu, Nov 12, 2009 at 02:15:18PM -0600, Jane Wang wrote:
> Reconfigure DMA transfer parameters to resume audio after system comming out of OFF state.

> Signed-off-by: Jane Wang <jwang@ti.com>

This looks OK to me but I'd like an ack from the OMAP folks.  Adding
Jarkko as well as he's the maintainer for OMAP audio.

> ---
>  sound/soc/omap/omap-pcm.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
> index 6a829ee..5e04390 100644
> --- a/sound/soc/omap/omap-pcm.c
> +++ b/sound/soc/omap/omap-pcm.c
> @@ -215,8 +215,13 @@ static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
>  
>  	spin_lock_irqsave(&prtd->lock, flags);
>  	switch (cmd) {
> -	case SNDRV_PCM_TRIGGER_START:
>  	case SNDRV_PCM_TRIGGER_RESUME:
> +		/* Reconfigure DMA transfer parameters
> +		 * in order to come back from OFF mode
> +		 */
> +		omap_pcm_prepare(substream);
> +		/* fall through */
> +	case SNDRV_PCM_TRIGGER_START:
>  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
>  		prtd->period_index = 0;
>  		/* Configure McBSP internal buffer usage */
> -- 
> 1.5.4.3
> 

Re: [PATCH 2/2] ASoC: OMAP: reconfigure DMA to resume audio

[Wang, Jane]

> -----Original Message-----
> From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
> Sent: Friday, November 13, 2009 7:51 AM
> To: Wang, Jane
> Cc: alsa-devel@alsa-project.org; linux-omap@vger.kernel.org;
> peter.ujfalusi@nokia.com; Jarkko Nikula
> Subject: Re: [PATCH 2/2] ASoC: OMAP: reconfigure DMA to resume audio
> 
> On Thu, Nov 12, 2009 at 02:15:18PM -0600, Jane Wang wrote:
> > Reconfigure DMA transfer parameters to resume audio after system comming
> out of OFF state.
> 
> > Signed-off-by: Jane Wang <jwang@ti.com>
> 
> This looks OK to me but I'd like an ack from the OMAP folks.  Adding
> Jarkko as well as he's the maintainer for OMAP audio.
> 
Thanks. I think my original patch failed to post on the mailing list. I will resend the patch and cc Jarkko.