Re: exynos4412: Audio dies after one day on kernel 4.0

[gabriel@unseen.is]

On 06/03/2015 02:05 AM, Krzysztof Kozlowski wrote:
> On 03.06.2015 04:51, gabriel@unseen.is wrote:
>> On 05/31/2015 08:47 AM, Krzysztof Kozlowski wrote:
>>> 2015-05-31 2:32 GMT+09:00  <gabriel@unseen.is>:
>>>>
>>>> Hello,
>>>>
>>>> I've been successfully using a self compiled linux kernel until version
>>>> 3.19 together with Debian Stretch.
>>>>
>>>> After upgrading the kernel to version 4.0 I see strange messages in the
>>>> logs i.e.
>>>>
>>>> May 27 22:44:01 pulseaudio[1027]: [alsa-sink-3830000.i2s-HiFi HiFi-0]
>>>> alsa-sink.c: ALSA woke us up to write new data to the device, but there
>>>> was actually nothing to write!
>>>> May 27 22:44:01 pulseaudio[1027]: [alsa-sink-3830000.i2s-HiFi HiFi-0]
>>>> alsa-sink.c: Most likely this is a bug in the ALSA driver
>>>> 'snd_soc_simple_card'. Please report this issue to the ALSA developers.
>>>> May 27 22:44:01 pulseaudio[1027]: [alsa-sink-3830000.i2s-HiFi HiFi-0]
>>>> alsa-sink.c: We were woken up with POLLOUT set -- however a subsequent
>>>> snd_pcm_avail() returned 0 or another value < min_avail.
>>>>
>>>>
>>>> I can easily play sound in perfect quality for approx the first 24h.
>>>> After that time the sound becomes distorted and is choppy/crackling.
>>>> After rebooting then the sound is optimal again.
>>>>
>>>>
>>>> I have tried to use kernel 4.0 with almost exactly the same
>>>> configuration than for 3.19 to no avail.
>>>>
>>>> Then somebody on
>>>> http://forum.odroid.com/viewtopic.php?f=82&t=13281&p=91186 gave me the
>>>> hint that the followin patch might solve the issue:
>>>>
>>>> https://github.com/prahal/linux/commit/5e60cfc9fa5101a346e29ef5f944fbbad300c72d
>>>>
>>>>
>>>> The patch did help something. I can now still play music after 2 days
>>>> but what happens is that each time I turn on music I get a choppy sound
>>>> for some time. That means the sound comes clear but every 2 seconds the
>>>> sound pauses for a fraction of a second. Which is somewhat comparable to
>>>> the issue earlier but without the heavy crackling - and that this goes
>>>> away after a couple of minutes.
>>>>
>>>>
>>>> But furthermore the sound has now simple cracklings. One in two second
>>>> approx. and they do not disappear.
>>>>
>>>>
>>>> Does anybody have an idea what could be the matter here?
>>>>
>>>> Thanks in advance.
>>>
>>> +Cc Robert, dmaengine list.
>>>
>>> Bisecting would be helpful. You could also try reverting following commits:
>>> 88987d2c75
>>> aee4d1fac8
>>>
>>> Other possible test case would be disabling runtime PM for pl330 DMA driver:
>>>
>>> for i in /sys/bus/amba/drivers/dma-pl330/*.[amp]dma/power ; do
>>>   echo "on" > ${i}/control
>>> done
>>>
>>
>> Thanks a lot Krzysztof,
>>
>> I have reverted 88987d2c75 and aee4d1fac8 from 4.0.4 and I have still
>> audio working after 1 and 1/2 day. Unluckily the alsa error message
>> occured still once but they don't seem to be the issue here.
> 
> 
> +CC Marek,
> 
> Robert, Marek, do you have any idea for the cause?
> 

I can now say for sure that the commits 88987d2c75 and aee4d1fac8 are
the cause for the problem. Audio was working now for 7 days.

Cheers,
Gabriel