Re: [FFADO-devel] udev rules for FireWire audio devices

[Adrian K. <ad...@dr...>]

On Mon, Apr 19, 2010 at 11:49:23PM +0200, Arnold Krille wrote:

> Is the juju stack / udev able to create devices with permissions
> depending on the connected device?

Yep. That's what my udev rule does: if it's an Alesis io14, then it's an
external audio card, hence grant access to it to the "audio" group.

> And more so: is this feasable? Isn't it easier to continue like before
> and have a group video/audio/firewire/whatever that is allowed access
> to the devices?

Since you don't have a static device (like /dev/raw1394) but many
dynamically created devices named /dev/fw*, these devices need to be
owned by somebody, preferrably not by root. ;)

So the approach is right: if the ID matches a FFADO-supported soundcard,
hand it over to the audio group.


> If this gets scripted, it would be an extra script not run by the
> normal installation routine. Or only run when either the install is
> run as root or an DESTDIR is defined. Doesn't make sense to install
> udev rules to the users home directory:-)

The easy approach would be to ship a static file ffado.rules inside the
tarball and rely on the packagers to install it to the right location.
Or have another install target like "scons udev-install", but this would
boil down to one copy call.


Let's see...

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