On 4/22/2009 5:30 PM, Jarkko Nikula wrote:> On Wed, Apr 22, 2009 at 4:56 AM, Joonyoung Shim <jy0922.shim@xxxxxxxxxxx> <mailto:jy0922.shim@xxxxxxxxxxx>> wrote:> > Add checking in hw_params and prepare to detect bufferless pcms(i.e. BT> <--> codec).> > Signed-off-by: Joonyoung Shim <jy0922.shim@xxxxxxxxxxx> <mailto:jy0922.shim@xxxxxxxxxxx>>> ---> 쟳ound/soc/omap/omap-pcm.c | 9 ++++++++-> 1 files changed, 8 insertions(+), 1 deletions(-)> > diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c> index 07cf7f4..6454e15 100644> --- a/sound/soc/omap/omap-pcm.c> +++ b/sound/soc/omap/omap-pcm.c> @@ -87,8 +87,10 @@ static int omap_pcm_hw_params(struct> snd_pcm_substream *substream,> 쟳truct omap_pcm_dma_data *dma_data = rtd->dai->cpu_dai->dma_data;> 쟧nt err = 0;> > + /* return if this is a bufferless transfer e.g.> + * codec <--> BT codec or GSM modem -- lg FIXME */> 쟧f (!dma_data)> - return -ENODEV;> + return 0;> > > I see exactly similar lines in s3c24xx-pcm.c but don't point now the use> case where this is used and I don't have idea what is this all about.> > Is this something where DAI driver or another end of connection is used> to provide clocking and the whole setup is then controlled with ALSA PCM> API? Somehow I have the feeling that would there be a better way to> achieve it than with dummy bufferless transfer? I tested this patch with the omap3 target having the twl4030 codec. Thetwl4030 codec driver supports the voice DAI to transfer pcm data betweenmodem and codec, and i added for test the dummy voice DAI in machinedriver. To transfer pcm data at modem <--> codec doesn't need DMA. > > > -- > Jarkko _______________________________________________Alsa-devel mailing listAlsa-devel@xxxxxxxxxxxxxxxxxxxx://mailman.alsa-project.org/mailman/listinfo/alsa-devel
