[alsa-devel] Fwd: Re: Realtek ALC889: HDA Intel and kernel 3.1 gives choppy sound (again)

[David Henningsson]

2011-12-14 18:32, Takashi Iwai skrev:
> At Wed, 14 Dec 2011 17:12:20 +0100,
> Colomban Wendling wrote:
>> Le 14/12/2011 15:48, Takashi Iwai a écrit :
>>> At Wed, 14 Dec 2011 15:32:08 +0100,
>>> Colomban Wendling wrote:
>>>> Here's my initial mail, but with gzipped outputs.
>>> Please don't drop Cc list.
>> Sorry, I fwd'ed the message and forgot to update the CClist, sorry.
>>
>>>> Le 08/11/2011 07:32, Takashi Iwai a écrit :
>>>>> At Mon, 07 Nov 2011 23:45:40 +0100,
>>>>> Colomban Wendling wrote:
>>>>>> Hi,
>>>>>>
>>>>>> Back to 3.0, the sound on my soundcard [1] started to be choppy, I
>>>>>> reported it [2] and it got fixed (thanks to Takashi Iwai!).
>>>>>>
>>>>>> However, the story repeated with 3.1 (and probably 3.0.8 or before [3]):
>>>>>> I've got similar choppy sound again.
>>>>>>
>>>>>> I bisected the few commits that happened on
>>>>>> sound/pci/hda/patch_realtek.c, and finally found the villain:
>>>>>>
>>>>>> "8974bd51 ALSA: hda/realtek - Fix auto-mute with HP+LO configuration"
>>>>>>
>>>>>> Reverting it from v3.1 fixes the problem.
>>>>> Does it?  Very weird.  This patch has nothing to do with the HD-audio
>>>>> controller side but purely a codec change.
>>>> Yep, I just check once again and it really fixes the problem here.
>>>>
>>>>>> master (94956ee) also suffers of the problem, but I couldn't test
>>>>>> without that commit because reverting it fails, too much changes happened.
>>>>> Did you try to pass position_fix=1 (or 2) option?
>>>>> Also, passing enable_msi=0 (or 1) may change anything?
>>>> I just tried with the 3 kernels:
>>>>
>>>> * vanilla v3.1
>>>> * vanilla 3.2-rc1 (master at 1ea6b8f)
>>>> * v3.1 with 8974bd51 reverted
>>>>
>>>> and none of the option changed anything: both vanilla always failed, the
>>>> third always succeeded.  Though, I haven't combined the options, just
>>>> tried each at once.
>>>>
>>>>> In anyway, please give alsa-info.sh output again with the fresh
>>>>> kernel.  Run it with --no-upload option and attach the output.
>>>> Here it is, for the 3 kernels cited above.
>>> I see really no difference between vanilla3.1 and fixed.
>>> The only difference is the NID 0x24, which is irrelevant with the
>>> output.  It concludes that the commit you found has nothing to do with
>>> the bug directly.  It's just a coincidence that it triggers
>>> something.
>>>
>>> Which output are you testing?  Does the problem happen on both HP and
>>> all line-outs?  Also, how are you testing?  How about the direct aplay
>>> with -Dhw like
>>> 	% aplay -Dhw foo.wav
>>> ??
>> Aha, you refined it!
>>
>> Even if I think it won't be really relevant any more (see below), what I
>> did before was basically `mplayer -ao alsa<file>` and listening.  The
>> first time I heard the problem I think I tried various players and
>> output methods that all did suffer of the problem, so I don't really
>> remember which ones.  Also, I (shame on me) ever only tested the rear
>> line out.
>>
>> So then, the news:
>>
>> First, playing with aplay -Dhw (after fighting to get pulseaudio
>> down...) doesn't change anything.
>>
>> But then, while all the rear outputs (L, SS, CS, RS) suffer of the
>> choppiness, the front one never does!
>> Moreover, if I plug something in the front output, sometimes [1] the
>> rear ones doesn't mute and stop "choppying"  (I have correct sound in
>> all outputs, rear and front).
> Hm, then this can be really related with the jack-detection.
> If so, the choppy sound is not because of the DMA position reporting
> but because of the continuous triggering of jack-detect events.
>
> If you built your kernel with the tracepoint support, you'll have
> /sys/kernel/debug/tracing/events/hda/enable file.  As root, run
>
>    # echo 1>  /sys/kernel/debug/tracing/events/hda/enable
>
> then check /sys/kernel/debu/tracing/trace file after some seconds.
> Do you get any events there?  Also, what about plugging/unplugging the
> headpohne jack?  After gathering the tracing info, disable again via:
>
>    # echo 0>  /sys/kernel/debug/tracing/events/hda/enable
>
> In anyway, if the jack-detection is really the problem, you can
> disable the auto-mute feature by changing "Auto-Mute Mode" enum to
> "Disabled".  Run "alsamixer -c0" and change the value.

Hmm, thanks for figuring this one out. Actually this is the third time I 
hear of jack detection flipping back and forth. I'm wondering if we need 
(and whether other OSes have?) a filter / flood protection on this 
stuff, and if so, how it works? I mean, nobody would notice half a 
second of delay on that switch anyway.

// David