[alsa-devel] [PATCH v2] ALSA: hda - Fix Skylake codec timeout

[David Henningsson]

On 2015-07-16 17:14, Yang, Libin wrote:
>> -----Original Message-----
>> From: David Henningsson [mailto:david.henningsson at canonical.com]
>> Sent: Thursday, July 16, 2015 4:39 PM
>> To: tiwai at suse.de; hui.wang at canonical.com; alsa-devel at alsa-
>> project.org; Yang, Libin; Lin, Mengdong
>> Cc: David Henningsson
>> Subject: [PATCH v2] ALSA: hda - Fix Skylake codec timeout
>>
>> When the controller is powered up but the HDMI codec is powered
>> down
>> on Skylake, the power well is turned off. When the codec is then
>> powered up again, we need to poke the codec a little extra to make
>> sure it wakes up. Otherwise we'll get sad "no response from codec"
>> messages and broken audio.
>
> Thanks for finding this issue.
>
> Could you please give us you test case? We didn't meet such issue
> before. I would like do a full test on it.

The test case is:

  - Install Ubuntu 15.04.
  - Upgrade to kernel 4.1.
  - Boot the new kernel.

Note: I believe Hui tested with 4.1 and got this error. In my case I 
have been running a hybrid kernel: Ubuntu 15.04, kernel 3.19.0-23.24 
(which has a backported i915 driver), and then the alsa-daily DKMS on 
top of that.

I can email you off-list with details about the machine I tested it on, 
if you like.

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic