[PlanetCCRMA] Reloading

Fernando Pablo Lopez-Lezcano nando@ccrma.Stanford.EDU
Wed Aug 28 09:53:01 2002

> Ah, OK! I had naively misremembered some of this, and thought that
> 'apt-get dist-upgrade' would automatically upgrade the kernel. Having
> followed these steps, the alsa-based sound is working fine!

Glad to hear that. Perhaps I should make things clearer in the
website. The only (potential) exception to the dist-upgrade
rule is actually the kernel. What makes it more confusing (and
difficult to explain) is that in some circumstances a
dist-upgrade can actually pull in a new kernel as part of the
upgrade process.

For example, take the initial dist-upgrade that happens when
you first install planet ccrma. Planet ccrma includes an
upgraded timidity++ package with support for alsa that gets
included in the upgrade (if timidity++ was actually installed,
of course). But there is no alsa in the system so alsa-lib
gets pulled in. But alsa-lib needs the driver so that
alsa-driver is now onboard. But the alsa-driver package needs
the alsa driver kernel modules to function. So the kernel
modules for that particular alsa driver gets pulled in. And of
course kernel modules without the matching kernel are no good
and so the proper kernel joins the party. End result: a lot of
stuff gets installed :-)

The situation is different the next time around. There is
already a complete set of alsa packages that satisfy all
dependencies. The fact that there is a new kernel available in
the repository does not change things because multiple
instances of the "kernel-up" package can be installed. I guess
that apt-get has no way of knowing which kernel is the right
one, in fact there is no "right" kernel to choose. So you have
to update the kernel manually and add the matching alsa driver
kernel modules package.

I'll stop here :-) It's not so simple... there was no real way
to configure the dependencies (both implicit and explicit) to
get a flexible system (ie: you are not _forced_ to run a
particular kernel) and make the automatic dependecies work all
the time - this is one of the reasons why the acpi laptop, up
and smp kernels have separate "branches" in the repository.
But most of the time it is just like magic and it works fine.

> If you'd like a guinea pig on whom to test USB-MIDI support for Planet
> CCRMA, I'd be eager to help.

Sure, let me try to find out more, I think there were a bunch
of changes in that area in alsa so the driver might be already
too old (the price of being in the bleeding edge of things
:-). I believe there is a nice page on the alsa wiki on this
matter, but I have not visited it (yet).

-- Fernando