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