[alsa-devel] about sound/core/pcm_lib.c:1997: capture read error (DMA or IRQ trouble?)

[Clemens Ladisch]

Akio wrote:
> > >   in my case, the sampling rate is 16k,
> > 
> > At 16 kHz, a 32-bit counter overflows after about 74.5 hours.
> 
> so the unit is samples not frames. does snd_pcm_prepare will reset
> the counter or not?

You said that snd_pcm_prepare() returns -EIO, so I guess the driver
does not.

> so I have to check out where is overflow occurred. which function
> should I dive into?

Some function in the driver.

> > Which driver are you using?
> 
> my platform is Freescale i.mx27 TO1, the audio driver is come from Freescale.

Then I'd suggest you'd ask Freescale.

In any case I cannot help you if you don't tell me where to find the
source code of the driver.


Regards,
Clemens