Re: alsa was Re: ABI coupling to hypervisors via CONFIG_PARAVIRT

From: Pavel Machek
Date: Thu Mar 15 2007 - 05:11:36 EST


Hi!

> So... in dsp, if I wanted to record sound, I did
>
> cat /dev/dsp > /tmp/foo; cat /tmp/foo > /dev/dsp
>
> If that worked, I had usable sound system, and if it broke, I knew it
> is kernel fault.
>
> With alsa it is
>
> download & install alsalib
> download & install alsautils
> create 1007 nodes in /dev
> launch alsamixer, figure out what to do from inadequate descriptions
> launch arecord, try to guess some suitable options
> launch aplay, try to guess some options
>
> ...if it does not work, it may be a kernel problem or userspace
> problem; I'm left with debugging both. That makes alsa pretty much
> untestable.

(Just for the record, I should note that networking is misdesigned in
similar way; that's why we have eth0 instead of /dev/eth0, and need
special tools to rename network interface. But this mistake dates to
BSD days or something, so we got used to it... and at least you do not
need to keep libnetwork up to date to keep your net devices working.

So networking provides _ugly_ hardware abstraction, but it provides
it).

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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