udev, dev/dsp and alsa

Message

Gentree · Post by **Gentree** » Wed Apr 19, 2006 10:47 am

I just attempted to update udev which I had had to mask at 070-r1 to prevent breakage.

this is now getting a bit old and causing some blockage so it tried a more recent "stable" version.

udev-087 :

no /dev/dsp , no alsa , no sound.

I retroed to 079-r1, same story.

These are marked stable so I assume they do work but what needs to be done get the sound subsystem back, that was not covered by etc-udpate ?

TIA , Gentree.

Ferdinando · Post by **Ferdinando** » Wed Apr 19, 2006 11:00 am

Have you added alsasound to the boot runlevel?

Bye

Gentree · Post by **Gentree** » Wed Apr 19, 2006 11:22 am

perhaps I should be more specific : alsa has been working for the last couple of years, updating udev fails to provided /dev/dsp and breaks it.

I dont regard sound as boot level service so it is in default

thx

micmac · Post by **micmac** » Wed Apr 19, 2006 12:27 pm

Maybe checking /var/db/pkg/sys-fs/udev-087/CONTENTS against installed files and removing the old left-overs helps?

Ferdinando · Post by **Ferdinando** » Wed Apr 19, 2006 1:03 pm

Lately udev has been providing coldplug functionality, but afaik it's up to alsasound to load the appropriate modules, and up to the modules to create /dev/snd/ and /dev/sound/; maybe it's simply missing the symlink (/dev/dsp should point to something in /dev/sound). I can't be more specific since I'm not on my box atm.

Bye

Gentree · Post by **Gentree** » Wed Apr 19, 2006 6:17 pm

alsasound does load the modules, then fails.

/dev/dsp is normally linked to /dev/sound/dsp

I would expect udev to manage all /dev/* not alsa , are you sure about that?

Thx.

Gentree · Post by **Gentree** » Wed Apr 19, 2006 6:25 pm

Code: Select all

 sys-fs/udev
    selected: 070-r1
   protected: 079-r1
     omitted: none

reinstalling -079

Code: Select all

bash-3.1#udevstart
bash-3.1#ls /dev/dsp
/dev/dsp
bash-3.1#ls -ail !$
ls -ail /dev/dsp
157110 lrwxrwxrwx 1 root root 9 2006-04-19 20:18 /dev/dsp -> sound/dsp
bash-3.1#/etc/init.d/alsasound
Usage: alsasound [ flags ] < options >

Normal Options:
    start stop restart pause zap
      Default init.d options.

Additional Options:
    save
      Extra options supported by this init.d script.

Flags:
    --quiet
      Suppress output to stdout, except if:
      1) It is a warning, then output to stdout
      2) It is an error, then output to stderr
    --nocolor
      Suppress the use of colors.

Configuration files:
    /etc/conf.d/alsasound    /etc/rc.conf

For more info, please run '/etc/init.d/alsasound help'.
bash-3.1#/etc/init.d/alsasound restart
 * Storing ALSA Mixer Levels ...                                          [ ok ]
 * Unloading ALSA ...                                                     [ ok ]
 * Unloading ALSA modules ...                                             [ ok ]
 * Loading ALSA modules ...
 *   Loading: snd-card-0 ...                                              [ ok ]
 *   Loading: snd-pcm-oss ...                                             [ ok ]
 *   Loading: snd-seq ...                                                 [ ok ]
 *   Loading: snd-seq-midi ...                                            [ ok ]
 * Restoring Mixer Levels ...
/usr/sbin/alsactl: set_controls:1119: snd_ctl_open error: No such file or direct
ory                                                                       [ !! ]
bash-3.1#ls -ail /dev/dsp
ls: /dev/dsp: No such file or directory
bash-3.1#ls -ail /dev/sound/dsp
ls: /dev/sound/dsp: No such file or directory

so it appears that it is not the udev upgrade that destroys /dev/dsp but restarting alsa afterwards.

alsa seems to trip itself up by removing both /dev/dsp and /dev/sound/dsp and then can no longer reload the sound controls for the now non-existant device.

can you make any sense of that?

TIA

micmac · Post by **micmac** » Wed Apr 19, 2006 7:44 pm

I'd just compile the alsa drivers statically into my kernel instead using modules.

Gentree · Post by **Gentree** » Wed Apr 19, 2006 7:53 pm

Is there a specific way in which you think that would help with this issue?

thx

micmac · Post by **micmac** » Wed Apr 19, 2006 8:17 pm

At least the Gentoo alsa script doesn't get any chance to mess around loading/unloading drivers.

Ferdinando · Post by **Ferdinando** » Thu Apr 20, 2006 9:16 am

Gentree wrote:I would expect udev to manage all /dev/* not alsa , are you sure about that?

Well, actually alsa registers the device with the kernel, and in a udev environment the kernel should generate an uevent to notify udev of the new device, so you're right; if the problem is with udev you should have some log of that somewhere in /dev/.udev/failed/ (I've got a lot of entries in there, though all works properly, so you could have some difficulties finding the proper entry). I don't know if that would be helpful though.
I've searched a bit for "/usr/sbin/alsactl set_controls snd_ctl_open error No such file or directory" and found a lot of threads but no real solution, apart from randomly changing the alsa configuration, or switching from the in-kernel driver to alsa-driver (or vice versa).
If that matters, here I'm using udev-090 with alsa-utils-1.0.11 and the alsa driver of kernel 2.6.16-gentoo-r2, and I've got no problem so far.
EDIT: for instance I have the successful log /dev/.udev/db/class\@sound\@dsp:

Code: Select all

N:sound/dsp
S:dsp
M:14:3

Bye

Gentree · Post by **Gentree** » Thu Apr 20, 2006 8:11 pm

Code: Select all

bash-3.1#ls /dev/.udev/failed
ls: /dev/.udev/failed: No such file or directory

hmm, I'll try switching to alsa-driver. I am currently using alsa-1.0.8 in my 2.6.11 kernel

Maybe there is a dependancy that is not controlled by portage.

Thanks your filling my in on how some of this works.

wjb · Post by **wjb** » Fri Apr 21, 2006 12:08 am

I had a 2.6.11 kernel with sound that worked for a long long time (with alsa and sound card driver built in as modules). This broke back in Jan/Feb sometime. I tried all sorts of things - for a while, running udevstart restored the sound (related things appeared in /dev that were not there before). The logs looked like the module loads worked, but they behaved as if they didn't. Eventually I tried building alsa and the driver into the kernel, and it all started working again.

Gentree · Post by **Gentree** » Sat Apr 22, 2006 9:41 am

thanks for that info, I've also found this kernel very reliable uptil now so I'd like to stick with it.

All this is getting a bit messy. This is turning into one of the those dependacy nightmares linux is famous for.

seems like more recent udev has been changed in a way that is no longer compatible with alsa-1.0.8/9

recent alsa-driver wont even compile against my nitro kerenel souces, some change in parameter count somewhere.

another reason for keeping this kernel is an incompatible update in reiser4.

Linux development seriously needs to start respecting some sort of backwards compatability principal in code rather than expecting everyone to dance around version matching all the time, I seem to spend more time maintaining this system than using it!

I prefer modules but I'll try building alsa in to see if that gets around the problems.

sgtrock · Post by **sgtrock** » Mon Apr 24, 2006 1:18 am

Before you give up completely, try compiling the generic kernel sources. Nitro is not guaranteed to be completely clean, after all. I've had my share of strange issues with it in the past.

Gentree · Post by **Gentree** » Mon Apr 24, 2006 6:30 am

Yes , I think at least the compile probs with recent alsa-driver is due to nitro-sources.

Hwvr, I have both / and portage on R4 at the moment so I'll need to do some heavy reorganising to try vanilla.

I'm pretty sure a more recent nitro would fix alsa but I want to keep 2.6.11 for compat with a R4 liveCD and a Suse installation.

Like I commented above , it's a lack of backwards compatibility on several fronts which is making this complicated.

For the record , making alsa built-in seems to work with udev-079 but not beyond. I may just stick with 070 until there is a pressing reason to do otherwise.

Thanks.

Bitspyer · Post by **Bitspyer** » Wed Apr 26, 2006 4:57 pm

Hmmm....Anyway, this isn't really a solution, but i fixed this with loading the kernel module snd-pcm-oss.

Then /dev looks like this: /dev/dsp -> sound/dsp

I'm using kernel-alsa, all sound modules are auto-loaded.

Gentree · Post by **Gentree** » Thu Apr 27, 2006 7:02 am

thx , what kernel , what udev?

linuxbum · Post by **linuxbum** » Fri Apr 28, 2006 3:26 am

I have used alot of Linux distro red hat 6, 7, 8, Suse 7, 8, 9, gentoo.

My server at home and work is Gentoo.

My laptops have been all of them.

Suse 9.3 right now on C640 Dell with 2915 card Wireless is a pain to get LEAP to work.

You will be happy with Suse as long as you never try and go beyond the installed number version.

I have had nothing but problems with number changes 7 to 8 8 to 9.

Bryan

Bitspyer · Post by **Bitspyer** » Fri Apr 28, 2006 8:57 am

@Gentree:
Kernel: gentoo-sources 2.6.16-r3

udev: 0.90