[alsa-devel] Crackly sound with dmix rate 48000

[Takashi Iwai]

At Mon, 09 Nov 2009 13:34:34 +0000,
Daniel Drake wrote:
> 
> Hi,
> 
> In our musical activities, the OLPC/Sugar platform uses csound which in
> turn uses ALSA for playing sounds.
> 
> On our latest XO hardware model, where we now use HDA instead of cs5536,
> we are experiencing some crackly sounds from our csound-based
> applications. Other apps are fine.
> 
> We discovered that changing the dmix rate from 48000 to 44100 solves the
> cracklyness.
> 
> What does this indicate?
> 
> Might csound be producing sounds at rate 44100, which dmix previously
> had to convert to 48000, which was too taxing to the system?

Might be.  Another possible problem is the position update bug.
Try to pass position_fix=1 option and/or bdl_pos_adj=0 to
snd-hda-intel module.


Takashi