Re: Is it time for remove (crap) ALSA from kernel tree ?

From: Olivier Galibert
Date: Mon Jun 25 2007 - 08:47:59 EST


On Mon, Jun 25, 2007 at 02:40:23PM +0200, Jan Engelhardt wrote:
>
> On Jun 25 2007 14:31, Takashi Iwai wrote:
> >> It was started in time when most cheap sound cards was without hw mixer.
> >> And .. when today you use ALSA on sound card without hw mixer still all
> >> this (past ?) problems are actual.
> >
> >Huh? I have no problems with soft mixing...
>
> Diverging from the discussion, how is soft mixing actually done? If it was done
> in userspace, it would need shared memory, or a back relay from kernelspace to
> userspace (and back again for the final output), otherwise I could not imagine
> how all alsa streams came together at one point.

SysV shared memory and semaphores, done in the alsa lib.

Yes, your kernel sound access library does shared mem, semaphores,
fork+exec and friends.

Back relay and virtual devices is the way it should have been done.

OG.
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