[PATCH] ALSA SOC driver for s3c24xx: 8 bit sound fix

[PATCH] ALSA SOC driver for s3c24xx: 8 bit sound fix

[Christian Pellegrin]

fixes playing/recording of 8 bit audio files.

Generated on  20081108  against v2.6.27

Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
---
 sound/soc/s3c24xx/s3c24xx-i2s.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/sound/soc/s3c24xx/s3c24xx-i2s.c b/sound/soc/s3c24xx/s3c24xx-i2s.c
index ba4476b..c18977b 100644
--- a/sound/soc/s3c24xx/s3c24xx-i2s.c
+++ b/sound/soc/s3c24xx/s3c24xx-i2s.c
@@ -261,10 +261,17 @@ static int s3c24xx_i2s_hw_params(struct snd_pcm_substream *substream,
 
 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S8:
+		iismod &= ~S3C2410_IISMOD_16BIT;
+		((struct s3c24xx_pcm_dma_params *)
+		  rtd->dai->cpu_dai->dma_data)->dma_size = 1;
 		break;
 	case SNDRV_PCM_FORMAT_S16_LE:
 		iismod |= S3C2410_IISMOD_16BIT;
+		((struct s3c24xx_pcm_dma_params *)
+		  rtd->dai->cpu_dai->dma_data)->dma_size = 2;
 		break;
+	default:
+		return -EINVAL;
 	}
 
 	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
--
1.4.4.4

Re: [PATCH] ALSA SOC driver for s3c24xx: 8 bit sound fix

[Takashi Iwai]

At Sat,  8 Nov 2008 08:44:16 +0100,
Christian Pellegrin wrote:
> 
> 
> fixes playing/recording of 8 bit audio files.
> 
> Generated on  20081108  against v2.6.27
> 
> Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
> ---
>  sound/soc/s3c24xx/s3c24xx-i2s.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/sound/soc/s3c24xx/s3c24xx-i2s.c b/sound/soc/s3c24xx/s3c24xx-i2s.c
> index ba4476b..c18977b 100644
> --- a/sound/soc/s3c24xx/s3c24xx-i2s.c
> +++ b/sound/soc/s3c24xx/s3c24xx-i2s.c
> @@ -261,10 +261,17 @@ static int s3c24xx_i2s_hw_params(struct snd_pcm_substream *substream,
>  
>  	switch (params_format(params)) {
>  	case SNDRV_PCM_FORMAT_S8:
> +		iismod &= ~S3C2410_IISMOD_16BIT;
> +		((struct s3c24xx_pcm_dma_params *)
> +		  rtd->dai->cpu_dai->dma_data)->dma_size = 1;
>  		break;
>  	case SNDRV_PCM_FORMAT_S16_LE:
>  		iismod |= S3C2410_IISMOD_16BIT;
> +		((struct s3c24xx_pcm_dma_params *)
> +		  rtd->dai->cpu_dai->dma_data)->dma_size = 2;
>  		break;

I don't think it's good to overwrite the global variables in this way.

And, what if playback and capture use the different formats in full
duplex streams...?


thanks,

Takashi

Re: [PATCH] ALSA SOC driver for s3c24xx: 8 bit sound fix

[chri]

Hi,

On Mon, Nov 10, 2008 at 7:50 AM, Takashi Iwai <tiwai@suse.de> wrote:
> At Sat,  8 Nov 2008 08:44:16 +0100,
>
> I don't think it's good to overwrite the global variables in this way.
>

I see. I just tried to keep the modifications minimal. Perhaps Ben
Dooks, the author of the code, can suggest a better way to proceed. I
will be happy to follow his suggestion.

> And, what if playback and capture use the different formats in full
> duplex streams...?
>

I dont' think that this is possible on the S3C24{1,4}0 since the
configuration registers are shared between playback and record path
(so this applies to sample frequency too for example). I guess you are
suggesting that given parameters should be checked against those of
the currently playing stream to see if they are compatible?


-- 
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."

Re: [PATCH] ALSA SOC driver for s3c24xx: 8 bit sound fix

[Takashi Iwai]

At Mon, 10 Nov 2008 08:20:13 +0100,
chri wrote:
> 
> Hi,
> 
> On Mon, Nov 10, 2008 at 7:50 AM, Takashi Iwai <tiwai@suse.de> wrote:
> > At Sat,  8 Nov 2008 08:44:16 +0100,
> >
> > I don't think it's good to overwrite the global variables in this way.
> >
> 
> I see. I just tried to keep the modifications minimal. Perhaps Ben
> Dooks, the author of the code, can suggest a better way to proceed. I
> will be happy to follow his suggestion.

OK.

> > And, what if playback and capture use the different formats in full
> > duplex streams...?
> >
> 
> I dont' think that this is possible on the S3C24{1,4}0 since the
> configuration registers are shared between playback and record path
> (so this applies to sample frequency too for example). I guess you are
> suggesting that given parameters should be checked against those of
> the currently playing stream to see if they are compatible?

Yes.  Without a proper check and/or hw_param constraints, the driver
thinks the streams are individual and allows apps to set up
independent parameters, which may result in a hardware error.

Creating hw constraints sharing both playback and capture streams is a
bit tricky and even racy.  But, it'd be much better than nothing.


thanks,

Takashi

Re: [PATCH] ALSA SOC driver for s3c24xx: 8 bit sound fix

[Mark Brown]

On Mon, Nov 10, 2008 at 08:30:19AM +0100, Takashi Iwai wrote:

> Yes.  Without a proper check and/or hw_param constraints, the driver
> thinks the streams are individual and allows apps to set up
> independent parameters, which may result in a hardware error.

Of course, since the driver isn't doing this yet we probably shouldn't
hold up any other fixes for it - it's needed anyway :/