Re: about sound/core/pcm_lib.c:1997: capture read error (DMA or IRQ trouble?)

[Akio <akioolin@gmail.com>]

> >   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?

> > what is the unit of the counter? period counts or samples?
> 
> I do not know what counter this could be.  I'm just guessing that _some_
> counter overflows; this would fit the symptoms you've described.

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

> >   I use strerr to get the error message, and it tell me "Input/Output
> >   Error"
> 
> This error code is returned by the driver.  Which driver are you using?

my platform is Freescale i.mx27 TO1, the audio driver is come from Freescale.
the audio codec is Freescale PC13783. the alsa core version is 1.0.13, kernel 
version is 2.6.19.3.

Thank you very much.

Best Regards,
Akio