Re: HDA buffer alignment

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



At Fri, 16 Mar 2007 14:21:34 +0100,
Joachim Deguara wrote:
> 
> "Takashi Iwai" <tiwai@xxxxxxx> wrote on 13:00 16/03/2007 +0100 :
> > At Fri, 16 Mar 2007 12:54:02 +0100,
> > Joachim Deguara wrote:
> >> >From the HDA spec it appears that the buffers written to the BDL and
> >> sent to a codec must be 128 byte aligned (section 4.5.1).  The alignment
> >> was not happening especially when playing 6 channels.  This patch set
> >> the alignment of buffers and periods to 128 bytes.
> > 
> > Good catch.
> > 
> > The changes look good to me, but please fold lines to fit within 80
> > chars.  Also, please give a sign-off for the patch to apply to the
> > upstream.
> 
> >From the HDA spec it appears that the buffers written to the BDL and
> sent to a codec must be 128 byte aligned (section 4.5.1).  The alignment
> was not happening especially when playing 6 channels.  This patch set
> the alignment of buffers and periods to 128 bytes.
> 
> Signed-off-by: Joachim Deguara <joachim.deguara@xxxxxxx>

Thanks, applied to HG tree now.


Takashi

> 
> diff -r f8284261b2be pci/hda/hda_intel.c
> --- a/pci/hda/hda_intel.c       Thu Mar 15 15:10:28 2007 +0100
> +++ b/pci/hda/hda_intel.c       Fri Mar 16 07:04:47 2007 +0100
> @@ -1087,6 +1087,10 @@ static int azx_pcm_open(struct snd_pcm_s
>         runtime->hw.rates = hinfo->rates;
>         snd_pcm_limit_hw_rates(runtime);
>         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
> +       snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
> +                                  128);
> +        snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
> +                                  128);
>         if ((err = hinfo->ops.open(hinfo, apcm->codec, substream)) < 0) {
>                 azx_release_device(azx_dev);
>                 mutex_unlock(&chip->open_mutex);
> 
> 
> 

-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/alsa-devel

[Index of Archives]     [ALSA User]     [Linux Audio Users]     [Kernel Archive]     [Asterisk PBX]     [Photo Sharing]     [Linux Sound]     [Video 4 Linux]     [Gimp]     [Yosemite News]

  Powered by Linux