Am Fri, 17 Aug 2012 01:54:34 -0700
schrieb Cinder <cinder@linuxwaves.com>:

> Hi, how do I make changes to permissions and access mode of device nodes persistent? At the moment I have to chown and chmod the /dev/snd/seq node every boot to make it accessible to my user. the other nodes are fine. Here's the output of ls -l /dev/snd/
> 
> total 0
> drwxr-xr-x  2 root root       60 Aug 17 18:44 by-path
> crw-rw----+ 1 root audio 116, 12 Aug 17 18:44 controlC0
> crw-rw----+ 1 root audio 116, 11 Aug 17 18:44 hwC0D0
> crw-rw----+ 1 root audio 116, 10 Aug 17 18:44 hwC0D3
> crw-rw----+ 1 root audio 116,  9 Aug 17 18:44 hwC0D4
> crw-rw----+ 1 root audio 116,  8 Aug 17 18:44 hwC0D5
> crw-rw----+ 1 root audio 116,  7 Aug 17 18:44 pcmC0D0c
> crw-rw----+ 1 root audio 116,  6 Aug 17 18:44 pcmC0D0p
> crw-rw----+ 1 root audio 116,  5 Aug 17 18:44 pcmC0D1p
> crw-rw----+ 1 root audio 116,  4 Aug 17 18:44 pcmC0D3p
> crw-rw----+ 1 root audio 116,  3 Aug 17 18:44 pcmC0D7p
> crw-rw----+ 1 root audio 116,  2 Aug 17 18:44 pcmC0D8p
> crw-------  1 root root  116,  1 Aug 17 18:44 seq
> crw-rw----+ 1 root audio 116, 33 Aug 17 18:44 timer
> 
> I need /dev/snd/seq to look look the others. I can't find the udev rule or configuration that creates these nodes. Many thanks for any consideration.

I have a hack for the same issue in my /etc/local.d/. A comment I put there
says this:

# this is caused by using devtmpfs, which creates nodes with root:root and 600;
# I believe this is fixed by udev upstream

So devtmpfs creates the device node before udev runs, but udev does not correct
the access permissions, which is however fixed by udev upstream (perhaps
already in ~arch?). Sadly I do not remember where I read this, but google should
be of help there.

HTH
-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup