[LAD] alsa card order
zotz at 100jamz.com
Wed Apr 29 13:01:41 UTC 2009
On Wednesday 29 April 2009 07:45:08 Simon Fielding wrote:
> On Tue, 2009-04-28 at 21:22 -0400, drew Roberts wrote:
> > > The naming system exists for a reason, i.e. to allow you to easily
> > > identify devices without remembering any cryptic numbers. It also
> > > allows you to change the name during runtime via sysfs in case you
> > > want to fix them up.
> > >
> > > > 1. I *want* stable indices, and
> > >
> > > Why?
> > Well, I don't care how I would do it so long as I can finally find a way
> > to do it.
> > I want to load up 1 box with 4 sound cards (preferably el cheapo USB
> > cards) and hoot the outputs of 4 radios to the inputs of the cards. (I
> > prefer identical cards if possible.) I want to tune each radio to a
> > different station and record each 24x7. now I want the stations to record
> > consistently.
> > So far I have not run across a solution that didn't assume different
> > cards. Any ideas anyone/
> > all the best,
> As far as I am aware, the only way to do anything like this is with
> udev. I don't have any spare sound cards in the office so I've done some
> experimenting with 2 identical mice. Running the following command
> udevadm info -a -p $(udevadm info -q path -n /dev/input/mouse0)
> for each mouse (soundcard in your case) replacing mouse0 with mouse1,
> mouse2 etc and comparing the results shows that the only way to uniquely
> identify them is by the usb port number eg :-
> Providing that your radio/soundcard/usb port triplets remain the same,
> either by never unplugging them, or by labelling them so that the same
> radio connects to the same soundcard connects to the same usb port every
> time, you could use the above ATTRS to write udev rules
> in /etc/udev/rules.d/ which will allow you to name your devices whatever
> you wish eg :-
> /dev/radios/luxembourg /dev/radios/texasbigbeat etc.
> Caveat: I have never written a udev rule in my life so you may need to
> do some research and testing of that yourself.
> Hope this is of at least some slight help and/or interest.
Thanks, I have got to try this out... And remember to report back...
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