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
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