At Wed, 19 Aug 2009 03:52:17 +1000, Damien Zammit wrote:

Digidesign Mbox 2 support for Linux - Damien Zammit 19/08/2009

dczammit@flop:~$ dmesg [132064.931715] ALSA sound/usb/usbaudio.c:3279: Sending Digidesign Mbox 2 boot sequence... [132064.934474] ALSA sound/usb/usbaudio.c:3306: device initialised! [132064.937473] ALSA sound/usb/usbaudio.c:3315: mbox2_boot: new boot length = 646 [132064.945769] ALSA sound/usb/usbaudio.c:2814: 36:2:2: add audio endpoint 0x3 [132064.950765] ALSA sound/usb/usbaudio.c:2814: 36:2:3: add audio endpoint 0x3 [132064.957314] ALSA sound/usb/usbaudio.c:2814: 36:3:2: add audio endpoint 0x4 [132064.961622] ALSA sound/usb/usbaudio.c:2814: 36:3:3: add audio endpoint 0x4 [132064.964575] ALSA sound/usb/usbaudio.c:2814: 36:3:6: add audio endpoint 0x4 [132064.971046] ALSA sound/usb/usbaudio.c:2814: 36:4:2: add audio endpoint 0x85 [132064.973545] ALSA sound/usb/usbaudio.c:2814: 36:4:3: add audio endpoint 0x85 [132064.979576] ALSA sound/usb/usbaudio.c:2814: 36:5:2: add audio endpoint 0x86 [132064.982522] ALSA sound/usb/usbaudio.c:2814: 36:5:3: add audio endpoint 0x86 [132064.986584] ALSA sound/usb/usbmidi.c:1357: created 1 output and 1 input ports [132064.986955] usbcore: registered new interface driver snd-usb-audio dczammit@flop:~$

dczammit@flop:~$ ls /proc/asound/M2/ id midi0 pcm0c pcm0p pcm1c pcm1p pcm2p stream0 stream1 stream2 usbbus usbid dczammit@flop:~$

dczammit@flop:~$ cat /proc/asound/M2/stream0 Digidesign Mbox 2 at usb-0000:00:1d.1-1, full speed : USB Audio

Playback: Status: Stop Interface 2 Altset 2 Format: 0x20 (24 bits) Channels: 2 Endpoint: 3 OUT (ASYNC) Rates: 8000 - 48000 (continuous) Interface 2 Altset 3 Format: 0x20 (24 bits) Channels: 2 Endpoint: 3 OUT (ASYNC) Rates: 8000 - 48000 (continuous)

Capture: Status: Stop Interface 5 Altset 2 Format: 0x20 (24 bits) Channels: 2 Endpoint: 6 IN (ASYNC) Rates: 8000 - 48000 (continuous) Interface 5 Altset 3 Format: 0x20 (24 bits) Channels: 2 Endpoint: 6 IN (SYNC) Rates: 8000 - 48000 (continuous) dczammit@flop:~$

dczammit@flop:~$ cat /proc/asound/M2/stream1 Digidesign Mbox 2 at usb-0000:00:1d.1-1, full speed : USB Audio #1

Playback: Status: Stop Interface 3 Altset 2 Format: 0x20 (24 bits) Channels: 2 Endpoint: 4 OUT (ASYNC) Rates: 8000 - 48000 (continuous) Interface 3 Altset 3 Format: 0x20 (24 bits) Channels: 2 Endpoint: 4 OUT (ASYNC) Rates: 8000 - 48000 (continuous)

Capture: Status: Stop Interface 4 Altset 2 Format: 0x20 (24 bits) Channels: 2 Endpoint: 5 IN (ASYNC) Rates: 8000 - 48000 (continuous) Interface 4 Altset 3 Format: 0x20 (24 bits) Channels: 2 Endpoint: 5 IN (SYNC) Rates: 8000 - 48000 (continuous) dczammit@flop:~$

dczammit@flop:~$ cat /proc/asound/M2/stream2 Digidesign Mbox 2 at usb-0000:00:1d.1-1, full speed : USB Audio #2

Playback: Status: Stop Interface 3 Altset 6 Format: 0x2 (16 bits) Channels: 2 Endpoint: 4 OUT (SYNC) Rates: 8000 - 48000 (continuous) dczammit@flop:~$

I fixed the broken pipes!! I can get speaker-test working, but I dont get any sound...

Is format 0x20 (S24_3LE) supported yet? I can't get it to work with jackd version 0.116.2

The format itself is supported well in the ALSA core. At least, I don't get any bug report regarding it.

Which interfaces/altsettings should I disable? I can't quite get the sound to come out.

Well, hard to say. Trial and error...

Takashi