# udev not creating device files for sound [probably solved]

## polyglot

I've recently reinstalled my system from scratch which solved some problems: https://forums.gentoo.org/viewtopic-t-486841-highlight-.html

My problem now is that udev is refusing to create some of my device files, particularly relating to sound.  I get no /dev/snd or /dev/sound directories as detailed in this post in the Multimedia section: https://forums.gentoo.org/viewtopic-t-489336-highlight-.html.  I originally thought it might be an alsa problem but now I think it's got more to do with udev; alsa is loading up correctly as far as I can tell and I can play sound.

However, I can currently only get sound by manually creating /dev/sound and running MAKEDEV audio in that directory to get the OSS device files.  Obviously I'm using the alsa-oss compatibility layer to make the OSS devices work; I don't really have OSS in my kernel.  That can be verified by loading & unloading alsa driver modules and noting that dsp and dsp1 start/stop working synchronously with what I see in /proc/asound/cards

udev has rules specifying that it should create devices in /dev/snd but then doesn't actually create them.  Any suggestions as to why it's not actually creating the files?  I do have coldplug running.

kernel config: http://shed.brodie-tyrrell.org/files/config-2.6.11.txtLast edited by polyglot on Tue Aug 22, 2006 5:11 am; edited 1 time in total

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## Dominique_71

You must follow this to install the ALSA drivers. Gentoo Linux ALSA Guide

I have both hotplug and coldplug running in my system.

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## nixnut

Moved from Installing Gentoo to Kernel & Hardware.

Postinstallation problem

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## polyglot

I did follow the ALSA installation guide and as stated in my previous post, alsa is working.  I'm using the modules provided with the kernel and they work just fine.

This is a udev problem: the only thing not working is the creation of userland device files, ie the contents of /dev/snd and /dev/sound.

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## polyglot

I had previously tried restarting hotplug/coldplug from the initscripts and it didn't help.  However, manually killing udev and running udevstart seems to have done the trick and now I get /dev/snd being created.

Perhaps fixed... I dunno if it'll come back on reboot but I can easily put a one-liner in init.d/local to kill & restart udev if I have to.

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## Dominique_71

Maybe at it come from the start order of the init scripts. I have alsasound and hotplug in my boot runlevel and coldplug in the defoult runlevel.

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## JeliJami

 *polyglot wrote:*   

> 
> 
> This is a udev problem: the only thing not working is the creation of userland device files, ie the contents of /dev/snd and /dev/sound.

 

change RC_DEVICE_TARBALL to "no" in /etc/rc.conf, and udev will recreate all necessary devices on next boot (but carefully read the comment above this option!)

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## Dominique_71

Good idea. The file have changed. /etc/rc.conf is mostly for X11 now, it is /etc/conf.d/rc now.

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## JeliJami

 *Dominique_71 wrote:*   

> Good idea. The file have changed. /etc/rc.conf is mostly for X11 now, it is /etc/conf.d/rc now.

 

damn typos   :Embarassed: 

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## Dominique_71

The problem with alsa is at udev must be able to load all the necessary drivers, but at all the linux distribution use modprobe to load the modules. Without loaded modules, you will never get any devices. I just get a strange issue with modules-update.

I am installing 2006.1 with ggc4.1.1 on a free partition. I install the tarball, change the use and clflags, run an emerge -e world, compile the kernel and the alsa-driver, and reboot. No sound device beside my first sound card, but with not all the modules that was loaded. I check /etc/modules.d/alsa and run modules-update again. /etc/modules.conf was not updated. It was no alsa conf in it.

The problem is at I just copied the alsa file in /etc/modules.d from my current installation over the new one. This file has an old date and modules-update just ignore it. I was in mc. F4, F2, F10 with the file. It get a new date and the problem was solved.

I think at the right way to go on the long run would be to incorpore adequate alsa rules in udev, so it will be no need to configure anything beside maybe for a musician that want things as the virmidi module.

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