[alsa-devel] salsa with noninterleaved needs irqpoll?

maarten van es maarten.h.van.es at gmail.com
Sat Apr 25 18:41:23 CEST 2009

>>> And what about the sample format?  I looked at the drivers; the two
>>> sound cards do not have a common sample format.
>>> Best regards,
>>> Clemens
> Thanks, the problem was indeed that I was setting hwparams that are
> not supported by the card. I do think salsa lib could return a more
> relevant error than "operation not permitted" and I'll see if I can
> come up with something for that.
> Right now though I am trying to figure out what snd_pcm_writen needs
> for its second parameter, void** bufs. I get the error "bad address"
> when passing in an array of pointers to a malloc-ed space big enough
> to hold a channels' worth of data. Sorry if I am missing obvious
> documentation about this, but what should I pass for this parameter?
> Regards
> Maarten

Hi again,

Ok, now I finally got everything working and am asking the following
mostly out of curiosity. The problem I had with snd_pcm_writen by the
way has to do somehow with using a chroot environment; everything
works when directly booting into the uclibc / salsa system. For it to
work I need to add "irqpoll" to the kernel boot options. Without this,
the card does not start playing (though no error messages from salsa)
and after a few seconds the kernel tells me to add irqpoll to the boot
options. On a glibc / alsa based system everything works fine without
this option as it does with a c-media card with salsa. What does it do
and why is it needed with the hdsp 9632 on a system with salsa?


More information about the Alsa-devel mailing list