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

[Hui Wang]

On 07/16/2015 11:31 PM, David Henningsson wrote:
>
>
> 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.
>

Here is a dmesg log, it is generated on a skl laptop with 
drm-intel-nightly kernel (v4.2), searching the keyword "timeout" in the 
text, you will find lots of timeout errors.

http://paste.ubuntu.com/11890651/