[alsa-devel] [PATCH 18/31] HDA patch_via.c: Add 48K sample rate limit for S/PDIF streams.

[Takashi Iwai]

At Tue, 6 Oct 2009 12:57:14 +0800,
Li Bo wrote:
> 
> Sorry, I meant better stability, not SNR.

What kind of stability do you mean?
A sort of hardware limitation?  Any software workaround is needed?


thanks,

Takashi

> On Tue, Oct 6, 2009 at 12:41 PM, Li Bo <liboat at gmail.com> wrote:
> > Hi, Takashi
> >  According to our HW test, S/PDIF at 48K sample rate has best SNR, so
> >  this limit can make S/PDIF work better.
> >
> > On Mon, Oct 5, 2009 at 11:14 PM, Takashi Iwai <tiwai at suse.de> wrote:
> >> At Mon, 5 Oct 2009 22:27:43 +0800,
> >> Li Bo wrote:
> >>>
> >>> [ALSA] HDA VIA: Add 48K sample rate limit for S/PDIF streams.
> >>>
> >>> Signed-off-by: Lydia Wang <lydiawang at viatech.com.cn>
> >>
> >> Any reason?
> >>
> >>
> >> Takashi
> >>
> >>>
> >>> Index: sound-2.6/sound/pci/hda/patch_via.c
> >>> ===================================================================
> >>> --- sound-2.6.orig/sound/pci/hda/patch_via.c  2009-10-05 15:11:02.000000000 +0800
> >>> +++ sound-2.6/sound/pci/hda/patch_via.c       2009-10-05 15:11:04.000000000 +0800
> >>> @@ -1228,6 +1228,7 @@
> >>>       .substreams = 1,
> >>>       .channels_min = 2,
> >>>       .channels_max = 2,
> >>> +     .rates = SNDRV_PCM_RATE_48000,
> >>>       /* NID is set in via_build_pcms */
> >>>       .ops = {
> >>>               .open = via_dig_playback_pcm_open,
> >>> @@ -1241,6 +1242,7 @@
> >>>       .substreams = 1,
> >>>       .channels_min = 2,
> >>>       .channels_max = 2,
> >>> +     .rates = SNDRV_PCM_RATE_48000,
> >>>  };
> >>>
> >>>  static int via_build_controls(struct hda_codec *codec)
> >>> @@ -2042,6 +2044,7 @@
> >>>       .substreams = 1,
> >>>       .channels_min = 2,
> >>>       .channels_max = 2,
> >>> +     .rates = SNDRV_PCM_RATE_48000,
> >>>       /* NID is set in via_build_pcms */
> >>>       .ops = {
> >>>               .open = via_dig_playback_pcm_open,
> >>> @@ -2657,6 +2660,7 @@
> >>>       .substreams = 1,
> >>>       .channels_min = 2,
> >>>       .channels_max = 2,
> >>> +     .rates = SNDRV_PCM_RATE_48000,
> >>>       /* NID is set in via_build_pcms */
> >>>       .ops = {
> >>>               .open = via_dig_playback_pcm_open,
> >>> @@ -3137,6 +3141,7 @@
> >>>       .substreams = 2,
> >>>       .channels_min = 2,
> >>>       .channels_max = 2,
> >>> +     .rates = SNDRV_PCM_RATE_48000,
> >>>       /* NID is set in via_build_pcms */
> >>>       .ops = {
> >>>               .open = via_dig_playback_pcm_open,
> >>> @@ -3581,6 +3586,7 @@
> >>>       .substreams = 2,
> >>>       .channels_min = 2,
> >>>       .channels_max = 2,
> >>> +     .rates = SNDRV_PCM_RATE_48000,
> >>>       /* NID is set in via_build_pcms */
> >>>       .ops = {
> >>>               .open = via_dig_playback_pcm_open,
> >>>
> >>
> >
>