[mythtv-users] Alsa only seems to work with Root user not mythtv user

[Mark Rissberger]

Michael T. Dean wrote:

> Mark Rissberger wrote:
>
>>   First off, I'd like to thank everyone that helped me get LIRC 
>> working with the PVR150.  It works like a dream now.  The problem 
>> that I have now seems like it may be a permission issue but I'm not 
>> sure where.  I can't use ALSA if I'm logged in as the mythtv user but 
>> it works fine if I'm logged in as root.  Here is what I get as root 
>> and as mythtv:
>>
>> [root at mythbox /]# aplay /usr/share/sounds/KDE_Startup.wav
>> Playing WAVE '/usr/share/sounds/KDE_Startup.wav' : Signed 16 bit 
>> Little Endian, Rate 22050 Hz, Mono
>> [root at mythbox /]# exit
>> exit
>>
>> [mythtv at mythbox /]$ aplay /usr/share/sounds/KDE_Startup.wav
>> ALSA lib pcm_dmix.c:797:(snd_pcm_dmix_open) unable to create IPC shm 
>> instance
>> aplay: main:533: audio open error: Permission denied
>>
>> Here are the permissions of /dev/audio and /dev/dsp:
>>
>> [mythtv at mythbox /]$ ls -l /dev/au*
>> crwxrwxrwx  1 mythtv root 14, 4 Oct 18 03:24 /dev/audio
>> [mythtv at mythbox /]$ ls -l /dev/dsp
>> crwxrwxrwx  1 mythtv root 14, 3 Oct 18 03:24 /dev/dsp
>>
>>
>> Any ideas????   
>
>
>
> ls -al /dev/snd
>
> to show ALSA devices.
>
> Most likely you'll see a group called "audio" or something.  Then, 
> just add mythtv user to the audio group.  If not (i.e. if owner and 
> group are root), fix the permissions (probably in udev scripts-- 
> http://www.reactivated.net/writing_udev_rules.html ).
>
> Mike
> _______________________________________________
>

Its really odd.  Now that I've changed the group on '/dev/snd/*',  
'/dev/shm', '/dev/dsp', and '/dev/audio' to mythtv, everything works 
fine.  Until I root plays a sound and then I'm right back to the above 
error msg, unable to create IPC shm instance.

Why would this be?  root must be doing something to the devices when it 
plays a sound.  Any ideas?

Thanks for the above help.  At least I've gotten this far.