Re: [PATCH] ALSA: hda - using POS_FIX_LPIB on Broadwell HDMI Audio

[Takashi Iwai <tiwai@suse.de>]

At Thu, 8 May 2014 05:48:04 +0000,
Yang, Libin wrote:
> 
> Hi Takashi,
> 
> I checked the wallclock counter. The counter is OK. But it failed to correct the position.

So, how wrong the position buffer is?  Is the problem intermittent?
Please elaborate more.


Takashi

> This issue happens when we play sound on HDMI audio. We have tried with aplay and paplay. 
> 
> I have tried the buffer size of 16384, 8192 and 4096 and with the sample rate of 48KHz and 44.1KHz.
> 
> Regards,
> Libin
> 
> > -----Original Message-----
> > From: Takashi Iwai [mailto:tiwai@suse.de]
> > Sent: Thursday, May 8, 2014 1:09 PM
> > To: Yang, Libin
> > Cc: alsa-devel@alsa-project.org; Lin, Mengdong; Pierre-Louis Bossart
> > Subject: Re: [PATCH] ALSA: hda - using POS_FIX_LPIB on Broadwell HDMI
> > Audio
> > 
> > At Thu,  8 May 2014 02:03:24 +0800,
> > libin.yang@intel.com wrote:
> > >
> > > From: Libin Yang <libin.yang@intel.com>
> > >
> > > Audio stream is not continuous if using position buffer on Broadwell
> > > HDMI audio. Sound is clipped.
> > > Fix this issue by using POS_FIX_LPIB.
> > 
> > That's odd.  The recent Intel hardware has a wallclock support, so the
> > position should be corrected by that.
> > 
> > In which situation did the problem happen?  Did it happen with every
> > application and any period/buffer setup?
> > 
> > 
> > Takashi
> > 
> > >
> > > Signed-off-by: Libin Yang <libin.yang@intel.com>
> > > ---
> > >  sound/pci/hda/hda_intel.c | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > > index b540ad7..9cd40c6 100644
> > > --- a/sound/pci/hda/hda_intel.c
> > > +++ b/sound/pci/hda/hda_intel.c
> > > @@ -993,6 +993,7 @@ static struct snd_pci_quirk position_fix_list[] = {
> > >  	SND_PCI_QUIRK(0x1565, 0x8218, "Biostar Microtech", POS_FIX_LPIB),
> > >  	SND_PCI_QUIRK(0x1849, 0x0888, "775Dual-VSTA", POS_FIX_LPIB),
> > >  	SND_PCI_QUIRK(0x8086, 0x2503, "DG965OT AAD63733-203",
> > POS_FIX_LPIB),
> > > +	SND_PCI_QUIRK(0x8086, 0x2010, "Broadwell HDMI audio",
> > POS_FIX_LPIB),
> > >  	{}
> > >  };
> > >
> > > --
> > > 1.8.3.2
> > >
>