[alsa-devel] Intel HD: ALC662 noise-bug on FitPC2i

[Takashi Iwai]

At Wed, 12 Dec 2012 14:14:57 +0100,
Bent Bisballe Nyeng wrote:
> 
> On 12/12/12 14:05, Clemens Ladisch wrote:
> > Bent Bisballe Nyeng wrote:
> >> When recording, audible clicking sounds are present in the resulting
> >> audio data.
> >>
> >> The corruption are composed of approximately 10 samples, and the
> >> nature of the corrupted values are such that they could come from an
> >> earlier buffer (the corrupted data resemble wav forms).
> > 
> > This looks like a problem with your HDA controller; either the memory
> > bus is overloaded so that some writes are dropped, or the hardware is
> > just buggy.
> > 
> > 
> > Regards,
> > Clemens
> 
> I tried to record some audio using windows 7 and here the noise was not
> present indicating that it is not buggy hardware.
> 
> Also, the system was not under load when the arecord call was made so if
> the memory bus was overloaded I need another way to verify this.
> 
> Are there any additional (useful) debugging info I can subtract from the
> system that will help aiding the debugging process?

Which sound backend are you using at all?  Does the problem appear if
you run with -Dhw for arecord?

If it's using dsnoop or PulseAudio, the accuracy of DMA position
reporting plays a big role.  In that case, changing position_fix
option cures often.


Takashi