Re: Must I have an `alias char-major-14 off' line?

[Dave Sherohman <esper@sherohman.org>]

On Wed, Jan 02, 2002 at 02:28:05AM +0200, Shaul Karl wrote:
> That is exactly the thing I do not understand. Since those lines are only comments, why does modprobe tries to locate module char-major-14 in the first place? (I do not want any sound.)

$ ls -l /dev | grep 14,
crw-rw----    1 root     audio     14,   4 Sep  8  1999 audio
crw-rw----    1 root     audio     14,   3 Sep  8  1999 dsp
crw-rw----    1 root     audio     14,   2 Sep  8  1999 midi00
crw-rw----    1 root     audio     14,   0 Sep  8  1999 mixer
crw-rw----    1 root     audio     14,   1 Sep  8  1999 sequencer
crw-rw----    1 root     audio     14,   6 Sep  8  1999 sndstat
^                                   ^    ^
|                                   |    +- Minor device number
|                                   +------ Major device number
+------------------------------------------ Character special file tag

(I've edited out a lot of that list, but you get the point.)

Some program or other is making a request to an audio device, probably
/dev/audio or /dev/dsp.  All of these device files are character (as
opposed to block) special files with major device number 14, so the kernel
looks for code which handles devices matching those characteristics to
service the request; by convention, such a driver is referred to by the
alias char-major-14.

/etc/modules.conf tells the kernel which external modules to look in
for external drivers.  Since it doesn't have support for char-major-14
internally, the kernel asks modprobe to search /etc/modules.conf and
load the appropriate module to handle the request.  You've commented
the relevant lines out, so modprobe can't find an appropriate driver
and logs a complaint that something appears to be wrong.

So, to answer your original question, there are two ways you can make
these messages go away:

1)  Add an "alias char-major-14 off" line to /etc/modules.conf, which
tells modprobe that it should just ignore requests for that device
because no appropriate driver exists.

2)  Configure all of your software to make no attempts to access any
sound-related devices.

Personally, I'd go for option #1.  It's a lot easier.

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