[alsa-devel] 3.6.0 regression, distorted sound failure while using jack and hd-audio

[Takashi Iwai]

At Sun, 07 Oct 2012 23:27:43 +0200,
Daniel Mack wrote:
> 
> (cc alsa-devel)
> 
> On 07.10.2012 21:34, Helge Hafting wrote:
> > My sound setup works fine with 3.5.4, but have serious problems with 3.6.0
> > 
> > It is sound through jack that breaks, simply using "aplay" directly with the
> > alsa device works.
> > 
> > When I use jack, my setup works fine with 3.5.4. But boot into 3.6.0,
> > and I get badly distorted sound as if using an extremely overdone reverb effect. 
> > And jack reports tons of xruns, several per second.
> > 
> > This can be worked around by going from 256 to 512 frames/period in the jack
> > settings. But that also double the latency, which makes keyboard playing less
> > pleasant.
> > 
> > It is not a case of 256 frames/period being (almost) too extreme for the machine. With kernel 3.5.4,
> > I can use 128 frames/period and get mostly ok sound, with only an occational 
> > xrun (and a correseponding pop in the sound). So I use 256 because that's solid.
> > But with 3.6.0, not even 256 is enough. And it is not an occational pop, but
> > awful distortion all the time.
> > 
> > I don't really know what has changed from 3.5.4 to 3.6.0. The hd-audio driver?
> > Something in alsa? Or the scheduling?
> > 
> > Machine: Dell precision M6600 laptop, 8GB, 2.2GHz quad-core i7.
> >          Usually at 800MHz to save power, this is enough for making sound.
> > Kernels: 64-bit 3.5.4 or 3.6.0
> > Distro: funtoo
> > 
> > Audio according to lspci:
> > 00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 04)
> > 
> > Please tell if there is anything I should try. I can test other kernel versions
> > or try patches.

This sounds like a known issue that has been fixed for 3.7-rc1.
As a workaround, try to pass position_fix=2 option to snd-hda-intel
module.


Takashi