Hi, On 08/15/2014 04:00 PM, Lionel wrote: > Hi Daniel. This is trace when i connect the midi controller. Thanks. This one here is the setup packet followed by the answer, which is the device descriptor: > ffff8801cbae2a80 1534946150 S Ci:2:000:0 s 80 06 0100 0000 0040 64 < > ffff8801cbae2a80 1534946409 C Ci:2:000:0 0 18 = 12010002 00000040 > a0174b34 01020301 0000 Which decodes to (some fields omitted): bcdUSB = 0x0200 idVendor = 0x17a0 idProduct = 0x344b bcdDevice = 0x0201 bNumConfigurations = 0 So this is clearly a bug in the firmware of your device, as bNumConfigurations = 0 doesn't make any sense. You basically have two options: ask the vendor to fix the bug, and send you instructions on how to update the firmware. Or we add a quirk to the USB layer in the kernel which sets bNumConfigurations to 1 for your device, hoping that that's the only bug in the firmware, which is not certain. If you want to go for the latter, you'd first need to build a kernel from the sources. As you said earlier you're on Ubuntu, some guidance is provided here: https://wiki.ubuntu.com/KernelTeam/GitKernelBuild Let me know when you managed to boot your own kernel. I'll send you a patch to test then. Best regards, Daniel ------------------------------------------------------------------------------ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user