How to set the order of multiple usb midi devices in jack ? ?

[pelorat]

Hi,
I'm running Debian Stretch with the great KXStudio repos enabled. I have a usb soundcard (Focusrite Scarlett 2i4) as well as a usb midi interface (M-Audio Midisport) and a usb controller. All these devices appear as snd_usb_audio with

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cat /proc/asound/modules

At each boot, these devices get a different index number, which makes restoring jack sessions painful, since I have to figure out which midi port to use if I wanna, say, send a midi track to an external synth. Which is I would like to do, really.

To make things worse, even if I only connect my soundcard and my midi interface, which makes only 2 midi outputs, I have no less than 7 midi playbacks ports appearing in QJackCtl.

So, ideally, I would like to make sure that each time I boot the computer, midi playback ports in QjackCtl will remain the same so that I can rename the ones corresponding to my actual hardware and be able to flawlessly restore sessions.

I would gladly appreciate any help. Thanks in advance !

[Jack Winter]

What does cat /proc/asound/cards say?

You can use the name of the card (inside of brackets) instead of the index number, like hw:Intel or hw:USB.

[pelorat]

Hi, thanks for your reply !

Here is the output of the command :

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0 [M1x1           ]: USB-Audio - MidiSport 1x1
                      M-Audio MidiSport 1x1 at usb-0000:00:1d.0-1.5, full speed
1 [USB            ]: USB-Audio - Scarlett 2i4 USB
                      Focusrite Scarlett 2i4 USB at usb-0000:00:1d.0-1.6, high speed
2 [DNSC2000       ]: USB-Audio - DN-SC2000
                      D&M DN-SC2000 at usb-0000:00:14.0-4, full speed

I tried to add these lines at the end of /usr/share/alsa/alsa.conf :

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options snd-usb-audio index=[hw:USB]
options snd-usb-audio index=[hw:M1x1]
options snd-usb-audio index=[hw:DNSC2000]

It had no effect, so I must have done something wrong. Is it the right file ? Is the syntax wrong ?

Thanks again for your time !

[Jack Winter]

Hi, thanks for your reply !

Here is the output of the command :

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0 [M1x1           ]: USB-Audio - MidiSport 1x1
                      M-Audio MidiSport 1x1 at usb-0000:00:1d.0-1.5, full speed
1 [USB            ]: USB-Audio - Scarlett 2i4 USB
                      Focusrite Scarlett 2i4 USB at usb-0000:00:1d.0-1.6, high speed
2 [DNSC2000       ]: USB-Audio - DN-SC2000
                      D&M DN-SC2000 at usb-0000:00:14.0-4, full speed

I tried to add these lines at the end of /usr/share/alsa/alsa.conf :

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options snd-usb-audio index=[hw:USB]
options snd-usb-audio index=[hw:M1x1]
options snd-usb-audio index=[hw:DNSC2000]

It had no effect, so I must have done something wrong. Is it the right file ? Is the syntax wrong ?

Thanks again for your time !

I don't know to be honest. I would add it to /etc/modprobe.conf (or what ever it's called on your system), since they are options when loading kernel modules. Try something like: options snd-usb-audio index=0,1,2 id=M1x1,USB,DNSC2000

But I think a better solution is referring to the card's names when using them. Like for jackd use hw:M1x1 or hw:USB, instead of hw:0 or hw:1.

[autostatic]

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$ modinfo snd-usb-audio | grep parm
parm:           index:Index value for the USB audio adapter. (array of int)
parm:           id:ID string for the USB audio adapter. (array of charp)
parm:           enable:Enable USB audio adapter. (array of bool)
parm:           vid:Vendor ID for the USB audio device. (array of int)
parm:           pid:Product ID for the USB audio device. (array of int)
parm:           device_setup:Specific device setup (if needed). (array of int)
parm:           ignore_ctl_error:Ignore errors from USB controller for mixer interfaces. (bool)
parm:           autoclock:Enable auto-clock selection for UAC2 devices (default: yes). (bool)

So you have to indicate a preferred index value and some kind of identifier for each device, Vendor and Product ID are an option:

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options snd-usb-audio index=1 vid=08bb pid=2706
options snd-usb-audio index=2 vid=xxxx pid=yyyy
options snd-usb-audio index=3 vid=xxxx pid=yyyy

You can list the Vendor and Product ID's with lsusb on the command-line:

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$ lsusb
Bus 001 Device 002: ID 8087:8000 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 002: ID 0b95:1790 ASIX Electronics Corp. AX88179 Gigabit Ethernet
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 004: ID 8087:07dc Intel Corp. 
Bus 002 Device 006: ID 0bda:5752 Realtek Semiconductor Corp. 
Bus 002 Device 002: ID 06cb:0af8 Synaptics, Inc. 
Bus 002 Device 010: ID 08bb:2706 Texas Instruments PCM2706 Audio Codec
Bus 002 Device 009: ID 413c:3016 Dell Computer Corp. Optical 5-Button Wheel Mouse
Bus 002 Device 007: ID 060b:2401 Solid Year 
Bus 002 Device 005: ID 05e3:0608 Genesys Logic, Inc. Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

[pelorat]

HI AutoStatic, thanks for your reply.

I've tried your method with no success. I think I am not editing the right file. So far I've tried :

• /usr/share/alsa/alsa.conf
  /etc/modules
  /etc/asound.conf

none of which worked. None of these files look like the old /etc/modprobe.d/alsa-base.conf that I was accustomed with.

Is there any other file that I'm not aware of ?

Thanks !

[autostatic]

Seems indeed you're not editing the right files. Does /etc/modprobe.d/ still exist? Then you could create a new file there, something like /etc/modprobe.d/midi-devices.conf and add the lines there.

[pelorat]

Yes, /etc/modprobe.d/ still exists. There was only one file in there called oss-compat.conf. I tried created midi-devices.conf and copy the lines but that didn't change anything.

[noedig]

I don't know if this will fit your workflow, but I use a2jmidid as a bridge from ALSA MIDI to JACK MIDI.
Specifically, I use it as:

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a2jmidid -ue

-e causes it to bridge your hardware MIDI devices; -u causes it to remove the ALSA port numbering, thus the resulting JACK ports will not have the ALSA numbering and thus look the same after every reboot.

[pelorat]

HI noedig, thanks for your reply,
That is a good idea, I wasn't aware of that option. Is it possible to start this automatically when starting qjackctl, the same way than a2j_control, or do you have to manually launch the program every time ?

[noedig]

Yes I'm sure you can just add it in the QJackCtl options. a2j_control controls a2jmidid, but I'm not sure how to use the -u option through a2j_control. I always just run a2jmidid directly, so I'm sure you can just replace a2j_control with a2jmidid -ue in your QJackCtl options.