[gentoo-amd64] Heads Up On Kernel-2.6.31 and Alsa

[gentoo-amd64] Heads Up On Kernel-2.6.31 and Alsa

[Frank Peters]

After configuring and compiling the new Linux kernel 2.6.31, my
sound system and sound programs no longer functioned.  I traced
this to one configuration variable under the Alsa sound devices:

SND_PCM_OSS_PLUGINS

This variable represents a new option for the Alsa OSS API, and
the default value seems to be "No."  But I assumed that setting
it to "Yes" would not make much difference, but it certainly did.

I really don't know what this option is all about (unless one
religiously follows all the minutiae of kernel development, Linux
can be full of surprises.)  The documentation says:

" If you disable this option, the ALSA's OSS PCM API will not 
support conversion of channels, formats and rates. It will  
behave like most of new OSS/Free drivers in 2.4/2.6 kernels."

So, apparently the improvement breaks all sound -- at least it
did for me.

If anyone has had a different experience, please report.  The new
option doesn't seem too thrilling.  I'd rather do all such conversions
using software in user space.

Frank Peters

Re: [gentoo-amd64] Heads Up On Kernel-2.6.31 and Alsa

[Volker Armin Hemmann]

On Sonntag 13 September 2009, Frank Peters wrote:
> After configuring and compiling the new Linux kernel 2.6.31, my
> sound system and sound programs no longer functioned.  I traced
> this to one configuration variable under the Alsa sound devices:
> 
> SND_PCM_OSS_PLUGINS
> 
> This variable represents a new option for the Alsa OSS API, and
> the default value seems to be "No."  But I assumed that setting
> it to "Yes" would not make much difference, but it certainly did.
> 
> I really don't know what this option is all about (unless one
> religiously follows all the minutiae of kernel development, Linux
> can be full of surprises.)  The documentation says:
> 
> " If you disable this option, the ALSA's OSS PCM API will not
> support conversion of channels, formats and rates. It will
> behave like most of new OSS/Free drivers in 2.4/2.6 kernels."
> 
> So, apparently the improvement breaks all sound -- at least it
> did for me.
> 
> If anyone has had a different experience, please report.  The new
> option doesn't seem too thrilling.  I'd rather do all such conversions
> using software in user space.
> 
> Frank Peters
> 

afaik it makes it possible to do exactly that - for oss using apps.