[linux-audio-user] Re: M-Audio MidiSport 2x2

[Ross Vandegrift]

On Thu, Jan 05, 2006 at 07:57:00PM +0800, Peter Clarke wrote:
> I'm interested by your comment "hotplug makes some real 
> trouble with USB audio devices".  I'm having trouble 
> getting the audio side of my Novation Speedio (a USB audio 
> and MIDI interface) to work properly (as per previous posts 
> on this list) - could this be related?  If so, what do I do 
> to run it without hotplug?

Well, it's kind of a catch22.  The problem is that the USB device
numbers don't seem to be constant.  My MIDI interface gets a
different address almost every time I plug it in.

There's no easy way to figure out where it got added, and if you have
multiple devices of the same make/model, you're actually SOL.  hotplug
events gets sent when the device is plugged - so when hotplug gets
called is the only point in time when you can know what numbers your
device came up with.

So to be be 100% sure, you must use hotplug.  If you're Speedio is the
only device you have, then it's pretty easy to just load the modules
by hand like you might for a PCI card - whatever USB numbers are
actually related to a device must be your box since you've only got
one.

FWIW - I don't think it'll help your audio issue.  If hotplugging
brings up the MIDI side, loading modules by hand is going to do the
same thing.  If you need some firmware, it could be an issue with the
firmware that you're loading.

-- 
Ross Vandegrift
ross at lug.udel.edu

"The good Christian should beware of mathematicians, and all those who
make empty prophecies. The danger already exists that the mathematicians
have made a covenant with the devil to darken the spirit and to confine
man in the bonds of Hell."
	--St. Augustine, De Genesi ad Litteram, Book II, xviii, 37