[alsa-devel] soc underrun problem

[dfoley]

Takashi Iwai wrote:
> At Tue, 17 Mar 2009 21:56:06 -0700,
> dfoley wrote:
>> I'm currently having a problem with playing wave files
>>
>> root at tsi-tpcxx:~# aplay /usr/share/sounds/alsa/Front_Center.wav
>> Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono
>> mapped channel 10 to 2
>> underrun!!! (at least 130.662 ms long)
>> underrun!!! (at least 140.809 ms long)
>>
>> I've narrowed it down to the commit ed3da3d9a0ef13c6fe1414ec73c9c1be12747b62 in linux-next/sound-2.6-tiwai.git.
>>    ALSA: Rewrite hw_ptr updaters
>>
>> The audio works fine, when I reverse this commit.
> 
> Could you build with CONFIG_SND_DEBUG_XRUN and set below?
> 	echo 1 > /proc/asound/card0/pcm0p/xrun_debug
> 
> It will show you why the playback skips.  It means usually the pointer
> callback is unstable.  The commit changed the xrun check more
> strictly.
> 
> 
> Takashi

root at tsi-tpcxx:~# echo 1 > /proc/asound/card0/pcm0p/xrun_debug
root at tsi-tpcxx:~# aplay /usr/share/sounds/alsa/Front_Center.wav
Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono
mapped channel 10 to 2
hda_codec: Lost interrupts? (stream=0, delta=20004, intr_ptr=2048)
XRUN: pcmC0D0p
underrun!!! (at least 58.490 ms long)
hda_codec: Lost interrupts? (stream=0, delta=20003, intr_ptr=2048)
XRUN: pcmC0D0p
underrun!!! (at least 58.254 ms long)
hda_codec: Lost interrupts? (stream=0, delta=20004, intr_ptr=2048)