Re: Re (2): Firewire IEEE 1394 cameras and Coriander.
On Tue, 12 Jun 2012 13:56:42 -0800, peasthope wrote:
> From: Camaleon <noelamac@gmail.com>
> Date: Mon, 11 Jun 2012 20:26:59 +0000 (UTC)
>> Did you finally reach some conclusion after reading the mentioned
>> documents?
>
> The Juju migration document has a new address and has expanded since
> then; my understanding has improved little.
>
> https://ieee1394.wiki.kernel.org/index.php/Juju_Migration
>
> It states,
> # /etc/udev/rules.d/example-firewire.rules # IIDC devices: industrial
> cameras and some webcams SUBSYSTEM=="firewire",
> ATTR{units}=="*0x00a02d:0x00010*", GROUP="video"
>
> Whereas Squeeze has no such rules.
> peter@joule:~$ ls /etc/udev/rules.d/
> 70-persistent-cd.rules 70-persistent-net.rules z60_hdparm.rules
Well, it says:
***
The following rules implement this device type dependent control over
permissions, using the example "video" group. These rules work with Linux
kernel 2.6.31 and later. These rules have been merged into /lib/udev/
rules.d/50-udev-default.rules of udev v144.
***
Indeed, there exists such a file there:
/lib/udev/rules.d/50-udev-default.rules
Look for the above mentioned firewire block (or better yet, "grep -i
firewire /lib/udev/rules.d/*") and if is not present anywhere, you can
create your own "/etc/udev/rules.d/example-firewire.rules" with the said
content (of course, you'll have to adjust to match your device ATTR).
Then reload udev or restart the system to test it.
> The Juju devices exist.
> peter@joule:~$ ll /dev/fw*
> crw------- 1 root root 252, 0 Jun 11 12:12 /dev/fw0
> crw-rw----+ 1 root video 252, 1 Jun 11 12:12 /dev/fw1
>
>> IIRC, there was a change coming from the kernel firewire stack, right?
>
> Yes, fw0 and fw1 are the Juju devices; but how can Coriander, started by
> peter, be acquiring the image from fw0 when the access is restricted to
> "crw------- 1 root root"?
(...)
You mean that running Coriander as root works fine? O:-)
Now seriously, you'll have to instruct udev to put the right perms on the
device, that is, the "video" group which peter should be a member of.
Greetings,
--
Camaleón
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