[linux-audio-user] edirol um-880 configuration help needed

[Chris Pickett]

Pedro Lopez-Cabanillas wrote:
> Chris Pickett wrote:
> 
>>>Clemens Ladisch wrote:
>>>>The ALSA driver supports both driver modes.
>>
>>I tried switching the UM-880 back to the FPT mode, and it works now.  I
>>don't know if that's a regression, but in any case I'll try out patches
>>for you if it's something you want to fix.
> 
> The "generic driver mode" descriptors aren't fully compliant with the USB MIDI 
> specification, because it doesn't have an AudioControl interface, which is 
> mandatory. You can say that an AudioControl interface is meaningless here 
> because the UM-880 has no audio function incorporated, only MIDI. That is 
> true, but in this case the class-specific AC interface descriptor will only 
> contain the header descriptor. Did you see a kernel/syslog complain about  
> "cannot find HEADER" or something like that? 

No, I just get:

usb 1-1: new full speed USB device using address 2

and then nothing works.

> The usb-midi OSS driver doesn't look for AC descriptor, so it can handle it. 
> But as Clemens said, that driver is not supported by Rosegarden.

Okay, thanks for the explanation.  I put a thread summary on how to get 
these devices working in the ALSA wiki:

http://alsa.opensrc.org/index.php?page=Edirol+UM-550+and+UM-880

Cheers,
Chris