[TAG] USB MIDI

[Bob van der Poel]

Hmmm, we might be getting somewhere ... another reboot, another test.


Thomas Adam wrote:
> On Sat, Dec 10, 2005 at 04:21:48PM -0700, Bob van der Poel wrote:
>> /proc/asound/cards). But, the device is NOT there to use. Trying to
>> use it generates an error; and 'aconnect' doesn't show it.
> 
> What error?
> 

bob$ aplaymidi -p72 midifile.mid
Cannot connect to port 72:0 - Invalid argument

Not the most helpful :( But, the port isn't there, so it makes sense.

>> However, plugging the unit in/out again shows it up.
>>
>> I'm wondering if a modprobe to something might force a registration. I
>> did try 'modprobe usb-midi' but no results there.
> 
> No results where?  modprobe, if it is successful won't return any
> output.  It's 'lsmod' that will help you here.

I was hoping that modprobe might reset something?

Okay, doing a lsmod before and after the little guy is working does show 
up something which might point to the problem:

Before a plugin/out (after boot) we have:

soundcore               7008  2 snd,usb_midi
usbcore               108348  7
          snd_usb_audio,snd_usb_lib,usb_midi,usblp,ehci_hcd,uhci_hcd

Afterwards, there is an additional line:

audio                  44032  0

And the others have changed to:

soundcore               7008  3 audio,snd,usb_midi
usbcore               108348  8
         audio,snd_usb_audio,snd_usb_lib,usb_midi,usblp,ehci_hcd,uhci_hcd

Really, just the difference in all this is that the 'audio' module has 
been added.

Also, there is a file /proc/asound/cards which does not change between 
no-work and work:

cat /proc/asound/cards
0 [AudioPCI       ]: ENS1371 - Ensoniq AudioPCI
                      Ensoniq AudioPCI ENS1371 at 0xec00, irq 10
1 [Interface      ]: USB-Audio - USB Uno MIDI Interface
                      M-Audio USB Uno MIDI Interface at
    usb-0000:00:10.1-1, full speed


Finally, the file /proc/asound/card1/midi0 has changed from being an 
empty file to:

bob$ cat midi0
USB Uno MIDI Interface

Output 0
   Tx bytes     : 197
Input 0
   Rx bytes     : 0


More thoughts?

-- 
Bob van der Poel ** Wynndel, British Columbia, CANADA **
EMAIL: bvdp at uniserve.com
WWW:   http://mypage.uniserve.com/~bvdp