Samson carbon 61 en Ubuntu? Novata total

Lunita escribió:

Mi pareja cree en teoría que con saber el USB ID puede crear una regla que fuerza al sistema udev a funcionar con un driver especifico.

Alguien escribió:

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

Lunita escribió:

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.

Alguien escribió:

Of my highest consideration.

I found a bug in the firmware in the midi controller Samson Carbon 61 V 1.25. That prevents successfully connect to the device.
The parameter bNumConfigurations is 0, The device is not compatible to any class compliant driver?

greetings

Alguien escribió:

Thanks Daniel!

You're welcome!

I decided to ask the vendor to fix the bug in the firmware. Do I have
any expectation of success?

Probably not. Most audio hardware vendors don't care about Linux.

What should be the best way to request
support for linux?

Well, I already offered to provide a patch to at least make the device
be recognized by the USB subsystem layer. After that has happened, we
can look at the other decriptors and see what they yield.

It's likely, however, that the device is not compatible to any class
compliant driver. I'd even assume the vendor set bNumConfigurations to 1
on purpose so that Windows doesn't look at the device. But that's just
guessing.

Let me know if you want to give such a patch a try.


Daniel

Lunita escribió:

Lo que si ahora no tengo ninguna placa de sonido ni sonido!

Alguien escribió:

Bus 002 Device 007: ID 17a0:344b Samson Technologies Corp.
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x17a0 Samson Technologies Corp.
idProduct 0x344b
bcdDevice 2.00
iManufacturer 1
iProduct 2
iSerial 3
bNumConfigurations 1

Much better

bInterfaceSubClass 3 MIDI Streaming

Ok, this is a class compliant MIDI interface that should just work (tm).
How did you test, and what does 'amidi -l' and 'dmesg' say?

Note that this is *not* an audio device, and will not appear as such in
your setup. It's *just* a MIDI device.

amidi -l say in ubuntu 12.04

no sound card found

But I just try it on ubuntu 14.04 and says

amidi -l
Dir Device Name
IO hw:1,0,0 Samson Carbon61 MIDI 1

Possibly there's a kernel difference, so just stick with the new version.

dmesg in ubuntu 14.04
[ 123.412090] usb 4-2: new full-speed USB device number 2 using ohci-pci
[ 123.587140] usb 4-2: New USB device found, idVendor=17a0, idProduct=344b
[ 123.587147] usb 4-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[ 123.587153] usb 4-2: Product: Samson Carbon61
[ 123.587158] usb 4-2: Manufacturer: Samson Technologies
[ 123.587163] usb 4-2: SerialNumber: 8D7751814956
[ 123.634774] usbcore: registered new interface driver snd-usb-audio

Looking good!

I think you should have no problems updating my system.

Yes, stay as up-to-date as possible


Have fun,
Daniel