[alsa-devel] poll blocked after prepare state

[Harald Schuster]

Hi
So I found out that the problem only occours when the dshare Plugin is  
used! When the normal hw is used the problem does not exist. Is there  
any knwon problem with the dshare plugin that the playback stops or is  
there a workaraund?
br Harald

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

> 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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>>>>
>>>>
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