[mythtv-users] No card showup in new myth 0.22 fc12 fresh install

Nick Morrott knowledgejunkie at gmail.com
Thu Dec 10 09:46:16 UTC 2009


2009/12/10 Claude Gélinas <claude at phyto.qc.ca>:
> Le mercredi 09 décembre 2009 04:09:52, Nick Morrott a écrit :
>> 2009/12/9 Claude Gélinas <claude at phyto.qc.ca>:
>> > fresh fc12 install
>> > myth from svn
>> > I have one pvr 500 and one HVR-1600 they look ok in dmesg but none are
>> > detected in mythtv-setup
>>
>> <snip>
>>
>> > what more do I need to check
>>
>> First, please check the relevant device permissions to ensure that the
>> user running mythtv-setup can access all of the capture devices.
>>
>> Nick
>>
> Cards show up like this:
>
> ls -l /dev/vid*
> crw-rw---- 1 root video 81,  0 déc  7 23:40 /dev/video0
> crw-rw---- 1 root video 81,  1 déc  7 23:40 /dev/video1
> crw-rw---- 1 root video 81,  6 déc  7 23:40 /dev/video2
> crw-rw---- 1 root video 81, 12 déc  7 23:40 /dev/video24
> crw-rw---- 1 root video 81,  4 déc  7 23:40 /dev/video25
> crw-rw---- 1 root video 81,  9 déc  7 23:40 /dev/video26
> crw-rw---- 1 root video 81, 10 déc  7 23:40 /dev/video32
> crw-rw---- 1 root video 81,  2 déc  7 23:40 /dev/video33
> crw-rw---- 1 root video 81,  7 déc  7 23:40 /dev/video34
>
> ls -l /dev/dvb/adapter0/
> total 0
> crw-rw---- 1 root video 212, 0 déc  7 23:40 demux0
> crw-rw---- 1 root video 212, 1 déc  7 23:40 dvr0
> crw-rw---- 1 root video 212, 2 déc  7 23:40 frontend0
> crw-rw---- 1 root video 212, 3 déc  7 23:40 net0
>
>
> so I've added mythtv user to the video group
> and now no V4L showup but I can see one DTV DVB (v3.X) as
> /dev/dvb/adapter0/frontend0
>
> but with an error message saying:
>  Can't open DVB frontend (/dev/dvb/adapter0/frontend0) for
> /dev/dvb/adapter0/frontend0.
>
> changing permission to 777 for all video* and dvb* I can see all my card. But
> what will apen on next reboot will the perm stay like this or should I change
> them for something better, more secur.
>
> With 777 perm I was able to see all of them.. I'm just not sure which one to
> chose for my card
>
> PVR 500 = mpeg IVTV for each video1 and video2
> HVR 1600 = one V4L for video0 and on DTV DVB for frontend0
>
> is it the wright choice

When you have multiple cards that create the same class of device
(e.g. /dev/videoX devices are created by the PVR-500 and HVR-1600) and
there is a chance that those devices may move around on subsequent
reboots, it is imperative to 'lock' the device nodes down to
consistent names. Ways to do this include:

i) via udev rules specific to your cards (more details on the wiki)
ii) when using ivtv-based card(s) you can use the 'ivtv_first_minor'
parameter during modprobe to control the node numbers created for
itvtv-based device nodes
iii) modprobe each card in sequence in rc.local, and then start the
services manually that rely on the devices (e.g. mythbackend).

To control permissions, I use udev rules to create additional nodes
and to control permissions where necessary. You could also use
rc.local to chown the devices before starting
mythbackend/mythtv-setup. When logging in from the console, you may
also need to create a new perms file in /etc/security/console.perms.d/
- and I guess SELinux could also get involved.

I might be a little off-base here, but in the past Fedora always
seemed to require more fiddling in this regard than other distros
mentioned on the list (in terms of device ownership/perms). Anyone
care to say whether this is still the case? I am not running F12 on
any backends to verify this.

Cheers,
Nick

-- 
Nick Morrott

MythTV Official wiki: http://mythtv.org/wiki/
MythTV users list archive: http://www.gossamer-threads.com/lists/mythtv/users

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