[alsa-devel] poll blocked after prepare state

[Harald Schuster]

Hi
I found out that the error occours when the snd_pcm_read_areas  
function is called in a special order. When the function  
snd_pcm_read_areas is not called or it is called between the  
snd_pcm_dshare_starts it works fine. The Codec is already running  
because the mic path is working fine.

pb_thread_func (alsa_dev.c): Underrun
snd_pcm_read_areas(pcm.c): Before snd_pcm_start()
snd_pcm_generic_start(pcm_generic.c):
snd_pcm_hw_start
snd_pcm_hw_start
pb_thread_func (alsa_dev.c): Underrun 0x74395c80
snd_pcm_write_areas(pcm.c): Before snd_pcm_start()
snd_pcm_dshare_start
snd_pcm_write_areas(pcm.c): Before snd_pcm_start()
snd_pcm_dshare_start
snd_pcm_write_areas(pcm.c): Before snd_pcm_start()
snd_pcm_dshare_start
snd_pcm_write_areas(pcm.c): Before snd_pcm_start()
snd_pcm_dshare_start



Zitat von Harald Schuster <schuster at technikum-wien.at>:

> We found out that in some cases after the underrun the  
> snd_pcm_dshare_start function is called and in some cases  
> snd_pcm_dshare_start and the snd_pcm_hw_start function is called.  
> When both functions are called the codec stops playback.
>
> Zitat von Takashi Iwai <tiwai at suse.de>:
>
>> On Mon, 25 Jun 2018 15:43:15 +0200,
>> Harald Schuster wrote:
>>>
>>> Hi
>>> The codec is the TI tlv320aic3x and the buffersize is set to 64 and
>>> the periodsize is set to 32 in the asound.conf. We use the pjProject
>>> for the audioprocessing and the internal period time is 4ms and the
>>> sample rate is 8000 Hz. The second codec is a USB codec which has no
>>> problems. Our scenario is that a incoming VOIP call is connected to
>>> the both codec (I2s and USB) and the USB codec starts the playback
>>> without any problems and the tlv320 sometimes works but when a
>>> underrun accours it crash!
>>
>> Is it really so hardware-specific problem?
>>
>> And, did you follow the recent development / fixes if it's about
>> dshare plugin?  There have been lots of changes.
>>
>> I'm not asking about updating the kernels.  The question is rather
>> about alsa-lib.
>>
>>
>> Takashi
>>
>>>
>>> best regards Harald
>>>
>>>
>>> Zitat von Takashi Iwai <tiwai at suse.de>:
>>>
>>>> On Mon, 25 Jun 2018 11:59:02 +0200,
>>>> Harald Schuster wrote:
>>>>>
>>>>>
>>>>> Hi
>>>>> We are not able to update our system. We are using USB codecs which
>>>>> are working fine but they are using the snd_pcm_hw_prepare function.
>>>>> The Problem only exists for the I2S codec in our system. When i
>>>>> changed the buffer size in the asound.conf for the codec the problem
>>>>> allready exists but it arise not so often because there is not so
>>>>> often a underrun. Is there any hint where i could lock for the
>>>>> problem?!
>>>>
>>>> Well, with that little information, it's hard to advice anything...
>>>>
>>>>
>>>> Takashi
>>>>
>>>>> br Harald
>>>>>
>>>>> Zitat von Takashi Iwai <tiwai at suse.de>:
>>>>>
>>>>> > On Fri, 22 Jun 2018 20:36:12 +0200,
>>>>> > Harald Schuster wrote:
>>>>> >>
>>>>> >>
>>>>> >> Zitat von Takashi Iwai <tiwai at suse.de>:
>>>>> >>
>>>>> >> > On Fri, 22 Jun 2018 15:29:21 +0200,
>>>>> >> > Harald Schuster wrote:
>>>>> >> >>
>>>>> >> >> I found out that an underrun occours and so the  
>>>>> pcm_prepare function
>>>>> >> >> for pcm_direct is called and then pcm_start_dshare is called. Both
>>>>> >> >> functions returns without any error but the playback path  
>>>>> is blocked
>>>>> >> >> in the snd_pcm_wait_nocheck function. I read that there  
>>>>> was an similar
>>>>> >> >> problem before in the group but i didn't found any  
>>>>> solution. Is this a
>>>>> >> >> problem in the driver and how can i go forward to fix it.  
>>>>> The codec is
>>>>> >> >> a tlv320aic3x-audio. Thanks for your help.
>>>>> >> >
>>>>> >> > Does this happen with the very latest alsa-lib git version?
>>>>> >> > Just to be sure.
>>>>> >> >
>>>>> >> >
>>>>> >> > Takashi
>>>>> >> > _______________________________________________
>>>>> >> > Alsa-devel mailing list
>>>>> >> > Alsa-devel at alsa-project.org
>>>>> >> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>>>> >>
>>>>> >> Hi
>>>>> >> We are using k4.1.15-6QP+ga2066af.
>>>>> >
>>>>> > I'm asking the alsa-lib, not kernel.
>>>>> >
>>>>> > And 4.1.x is very old...  Please check either 4.17.x or latest Linus
>>>>> > tree whether the problem persists, too.
>>>>> >
>>>>> >
>>>>> > Takashi
>>>>> > _______________________________________________
>>>>> > Alsa-devel mailing list
>>>>> > Alsa-devel at alsa-project.org
>>>>> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
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