On Sun, 9 Mar 2008 15:57:16 -0700
"Mark Knecht" <markknecht(a)gmail.com> wrote:
On Sun, Mar 9, 2008 at 3:52 PM, drew Roberts
<zotz(a)100jamz.com> wrote:
On Sunday 09 March 2008 18:44:21 Mark Knecht wrote:
Hi,
I'm aware of and use standard Alsa methods to keep different
sound cards in the same system straight as far as Alsa is
concerned. I'm wondering what the proper process would be to
keep 3 HDSP9652's which are physically in the same system, or
multiple USB sound devices external to the system, straight as
far as Alsa is concerned. I'd like to know that a certain card
always will be always be card 0, card 1 or card 2. I do not want
Alsa or Linux to make this decision for me and I certainly don't
want Alsa to change them from boot cycle to boot cycle.
What's the process to determine which identical card is
which? Do you need to determine some sort of card specific
hardware ID and then write udev rules or is there some way to do
this within Alsa?
I needed to solve this problem a while back. The best help I got
was telling me it was not possible.
Humm, that's a pretty glaring disappointment, assuming it's true, and
I have no reason to believe it isn't.
>
> I would be very interested to learn that there is a way. I got a
> lot of info that would help with non-identical cards though.
I have not tried this but maybe well crafted udev rules could help ?
The page
gives hints about matching device names to data read from sysfs.
Reading this doc, it looks like you might find info that uniquely
identify each of your cards using the command
"udevinfo -a -p $(udevinfo -q path -n /dev/snd/<yourdevice>)" and craft
you local rules from there.
This might be a question worth asking on alsa-users too.
HTH
--
David