[mythtv-users] Second PVR not seen my MythTVSetup, possible permission problem?

[Fred Squires]

On Wed, Mar 11, 2009 at 7:21 PM, Brian Wood <beww at beww.org> wrote:
> On Wednesday 11 March 2009 17:06:50 Michael T. Dean wrote:
>> On 03/11/2009 05:21 PM, Brian Wood wrote:
>> > Trying to add 2 PVR-150s to a newly built machine.
>> >
>> > The first card (/dev/video0) works just fine.
>> >
>> > I can't add the second card, usually I can just scroll through the
>> > available devices, but I can only get /dev/video0. If I manually set it
>> > to video1 it says it can't open the card.
>> >
>> > Boot logs show both cards being initialized normally.
>> >
>> > Both devices appear to be there:
>> >
>> > ls -l /dev/vid*
>> > lrwxrwxrwx  1 root root      6 2009-03-10 17:41 /dev/video -> video0
>> > crw-rw----+ 1 root root 81,  0 2009-03-10 17:41 /dev/video0
>> > crw-rw----  1 root root 81,  1 2009-03-10 17:41 /dev/video1
>> > crw-rw----+ 1 root root 81, 24 2009-03-10 17:41 /dev/video24
>> > crw-rw----  1 root root 81, 25 2009-03-10 17:41 /dev/video25
>> > crw-rw----  1 root root 81, 32 2009-03-10 17:41 /dev/video32
>> > crw-rw----  1 root root 81, 33 2009-03-10 17:41 /dev/video33
>>
>> Meaning that you will only find that device in mythtv-setup's drop down
>> if you run mythtv-setup as root.
>>
>> > This looks correct to me, except:
>> >
>> > I don't understand what the "+" is after the video0 device. I don't think
>> > it's the suid bit, or any of the things I'm familiar with.
>>
>> Permissions going above and beyond those representable with the standard
>> POSIX permissions...  Translation: ACL.
>>
>> > But the device with the "+" works, the one without it does not. I'd just
>> > add the "+", if I had any idea what it might be.
>>
>> So, either a) run mythtv-setup as root (assuming, also, that mythbackend
>> runs as root) or b) change the *nix permissions on your device entries,
>> or c) set an equivalent ACL on the second card's device nodes.
>
> See my followup, both cards now show up in the dropdown and work properly,
> both video0, which has the +, and video1, which does not.
>
> Guess I'll have to look into ACLs. Is this a Fedora/CentOS only thing? I
> haven't used Fedora in years, mainly use Gentoo and Debian.
>
> I was testing the latest MythDora, before I ship it to a friend to install,
> hence the Fedora-based system. I have spoken with the MythDora folks about
> the matter.
>
> Thanks for the pointer(s).
>
> --
> beww
> beww at beww.org

ACLs are a pretty standard thing these days, Mac OS X added them in
10.4 I believe.
It stands for Access Control List, and they allow more fine grained
control over permissions.
For instance, you could deny delete for your group, so even though the
group could read and write, they wouldn't be able to delete the file,
or you could allow a second group to have only read permission while
the group in the POSIX permissions could have read and write.

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