[linux-audio-user] Midi Usb interface

[Clemens Ladisch]

Dave Phillips wrote:
>     1. I put the USB driver on the blacklist in /etc/hotplug/blacklist
> to force a particular ordering of my cards.

You don't need to put the driver into the blacklist to force a
particular ordering.  Just make sure that all driver modules have
correct "index" parameters in /etc/modprobe.conf (or whatever module
configuration file your distribution uses):

options snd-whatever index=0
options snd-usb-audio index=1

> I load the driver and firmware with this script:
>
>         modprobe snd-usb-audio
>         fxload -I /.../ezusbmidi2x2.ihx -D /proc/bus/usb/001/003

In theory, snd-usb-audio should be loaded after the firmware.

> Can I automate this so I don't have to use the script ?

Put the script into /etc/hotplug/usb, and create another file named
scriptname.usermap containing the vendor/product IDs of the device.
The files I'm using in the loader for M-Audio's closed source firmware
are available here:
<http://cvs.sourceforge.net/viewcvs.py/usb-midi-fw/midisport-firmware/>

>     2. The firmware script requires a USB ID. Is there some way to have
> the script find that number, instead of me having to look it up via 'cat
> /proc/bus/usb' ?

The kernel passes the usbfs file name to the hotplug script in the
environment variable DEVICE.  (fxload will use this variable by
default.)

>     3. More of a seq24 problem, but: When I start seq24 and load a
> previous session I *must* have my synths loaded in their original order,
> else I have to reassign every sequence port/channel to the new ordering,
> which can be a real pain. Is there anyone else who would like to see
> more flexibility in relocating device numbers ?

You could try "modprobe snd-seq-dummy ports=10" and connect those
ports by hand to your synths, but then you'd have quite unintuitive
port names.

> I'm thinking that it's much easier to redefine one device's ID

Currently, ALSA doesn't allow to choose/change the client number of
software synthesizers.

> than to redefine potentially hundreds of sequence patterns.

It would be nice if sequencers would support assigning ports by name.
The MMA has defined a meta event for this, but AFAIK nobody uses it.


Regards,
Clemens