[Pkg-alsa-devel] Bug#439870: closed by Elimar Riesebieter <riesebie at lxtec.de> (Re: Bug#439870: Bug#439870: Bug#439870: aplay fails to load my driver module snd-sb16)

[David Lawyer]

On Sun, Nov 02, 2008 at 07:12:14PM +0000, Debian Bug Tracking System wrote:
> 
> This is an automatic notification regarding your Bug report
> which was filed against the alsa-utils package:
> 
> #439870: aplay fails to load my driver module snd-sb16
> 
> It has been closed by Elimar Riesebieter <riesebie at lxtec.de>.
> 
> Their explanation is attached below along with your original report.
> If this explanation is unsatisfactory and you have not received a
> better one in a separate message then please contact Elimar Riesebieter <riesebie at lxtec.de> by
> replying to this email.
> 
> 
> -- 
> 439870: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=439870
> Debian Bug Tracking System
> Contact owner at bugs.debian.org with problems

> Date: Sun, 2 Nov 2008 20:07:32 0100
> From: Elimar Riesebieter <riesebie at lxtec.de>
> Subject: Re: [Pkg-alsa-devel] Bug#439870: Bug#439870: Bug#439870: aplay
> 	fails to load my driver module snd-sb16
> To: David Lawyer <dave at lafn.org>
> Cc: 439870 at bugs.debian.org, 439870-done at bugs.debian.org
> 
> * Elimar Riesebieter [070916 22:30 +0200]
> > On Sat, 15 Sep 2007 the mental interface of
> > David Lawyer told:
> > 
> > > On Fri, Sep 14, 2007 at 08:04:13PM +0200, Elimar Riesebieter wrote:
> > [...]
> > > > Sorry, are you running a 2.4 kernel? modutils are deprecated in
> > > > etch/lenny/sid since we are running only 2.6 kernels here.
> > > 
> > > No, I'm running 2.6.21.  The same "sound" file is in /etc/modprobe.d
> > > but I didn't realize this.  It seems that alsa creates the "sound"
> > > file as well as other files in both the modprobe.d and modutils
> > > directories.  Look at the package list for alsa-base.
> > 
> > This is fixed in 1.0.14-2 ;) But anyway, you have to load snd-pc16
> > at boottime!
There is no such module as snd-pc16.
> 
> ISA modules have to be loaded by hand vi /etc/modules.
If so, I think this is a bug.  After all, I ran the slow configuration
program for alsa and it found the correct module for my sound card and
wrote in /etc/modprobe.d/sound: alias snd-card-0 snd-sb16 (where
snd-sb16 is the module for my sound card).  The configuration
completed without error and without any notice that loading the module
wouldn't happen when I run say aplay.

So this is a bug since anything successfully configured should work.
It doesn't load because the program fails prior to the point where it
loads the module.  This can be seen since if one first creates
/dev/snd/controlC0 alsa works OK and loads the module.  However
controlC0 doesn't get created.  One way to create controlC0 is just to
load the snd-sb16 module.

Here's another way to create it:  Put "M snd/controlC0 c 116 0" into
/etc/udev/links.conf.  If only this is done, it turns out that this
device can only be used by root (you need to be root to use sound) due
to restrictive permissions on the device.  But one can give users
belonging to the group "audio" the right to use it by specifying so in
/etc/udev/rules.d/91-permissions.rules.  Then people who use sound are
put into the audio group resulting in them being able to use audio.
There still exists the problem that the permissions on the device don't
get set as specified until the 2nd time you try to use use audio. 

So I think that the also sound program should be modified to either
load the module before it tries to access the non-existent controlC0
device, or the alsa configuration process should modify the
configuration in /etc/udev/links.conf so that controlC0 gets created
at boot-time and also get the udev people to fix the permission
problem with udev.  Perhaps alsa only needs to do one of the above if
one has an ISA card.

Another fix, that would work in my case is to look for controlC0 in
/dev/.static/dev/snd in case it's not found in /dev/snd

> Elimar
> 
> -- >what IMHO then?  IMHO - Inhalation of a Multi-leafed Herbal
> Opiate ;) --posting from alex in debian-user--



> Date: Mon, 27 Aug 2007 16:51:55 -0700
> From: David Lawyer <dave at lafn.org>
> Subject: aplay fails to load my driver module snd-sb16
> To: submit at bugs.debian.org
> 
> Package:alsa-utils
> Version: 1.0.14-1
> 
> When I type aplay ..., there is no sound and the sound modules fail to
> load.  I used strace to find out why.  aplay tries to open
> /dev/snd/controlC0 and then tries /dev/aloadC0.  Both fail to open
> since they don't exist.  After trying in vain C0, C1, C2, ... aplay
> gives up and exits with an error message "cannot find card ' '".
> 
> Well, I do have both devices it tried to open but they are both in the
> /dev/.static/dev/ directory.  So why is it looking in the wrong place
> for them?  My card is not plug-and-play and is thus not detected at
> boottime so nothing for it is put into the /dev directory.  But of
> course it's driver mod. snd-sb16 can find the card and use it.  So if
> I give the command "modprobe snd-sb16" sound works, although it still
> has a bug or two as I reported in another bug report.  I would rather
> not load the sound modules until I'm ready to start sound and don't
> want to auto-load them at boot time.  I've only got 32 MB of memory
> and aplay is supposed to load the modules by loading snd-sb16 which
> then loads a lot more sound modules per the dependency tree.
> 
> 			David Lawyer
> 

			David Lawyer