Re: usb 1-3: Product: BBC micro:bit CMSIS-DAP not recognised

[dima.pasechnik@cs.ox.ac.uk]

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On Mon, Dec 19, 2022 at 04:00:29PM +0100, Greg KH wrote:
> On Mon, Dec 19, 2022 at 12:57:43PM +0000, dima.pasechnik@cs.ox.ac.uk wrote:
> > this is a popular in UK education board: https://microbit.org/
> > - the currently sold (Version 2) one. It does on the same USB 3 things:
> >   mass storage, ACM, and serial. Serial appears unknown to the kernel.
> > 
> > With Linux kernel 6.0.8 on x86_54, and various USB serial drivers installed, upon plugging into USB
> > port, I see in dmesg:
> > 
> > [45460.035306] usb 1-3: new full-speed USB device number 10 using xhci_hcd
> > [45460.166959] usb 1-3: New USB device found, idVendor=0d28, idProduct=0204, bcdDevice=10.00
> > [45460.166965] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> > [45460.166967] usb 1-3: Product: BBC micro:bit CMSIS-DAP
> > [45460.166968] usb 1-3: Manufacturer: Arm
> > [45460.166970] usb 1-3: SerialNumber: 9905360200052833525e24a702a68552000000006e052820
> > [45460.172168] usb-storage 1-3:1.0: USB Mass Storage device detected
> > [45460.172538] scsi host1: usb-storage 1-3:1.0
> > [45460.173203] cdc_acm 1-3:1.1: ttyACM0: USB ACM device
> > [45460.175258] hid-generic 0003:0D28:0204.0005: hiddev96,hidraw0: USB HID v1.00 Device [Arm BBC micro:bit CMSIS-DAP] on usb-0000:00:14.0-3/input3
> > [45460.175581] usbserial_generic 1-3:1.4: The "generic" usb-serial driver is only for testing and one-off prototypes.
> > [45460.175585] usbserial_generic 1-3:1.4: Tell linux-usb@vger.kernel.org to add your device to a proper driver.
> > [45460.175587] usbserial_generic 1-3:1.4: device has no bulk endpoints
> > [45460.175818] usbserial_generic 1-3:1.5: The "generic" usb-serial driver is only for testing and one-off prototypes.
> > [45460.175821] usbserial_generic 1-3:1.5: Tell linux-usb@vger.kernel.org to add your device to a proper driver.
> > [45460.175823] usbserial_generic 1-3:1.5: generic converter detected
> 
> Is there some script adding this device id to the generic driver such
> that you are binding to this device?  Did the script come with the
> device?

It didn't bind to a /dev/ttyUSB* device, even if I manually loaded the corresponding modules.
Then I read somewhere I had to do 

    echo 0d28 0204 >/sys/bus/usb-serial/drivers/generic/new_id

(the numbers there are VID and PID of the board)
to make it recognisible by the driver.

Unfortunately I can't easily tell you how it behaved without it,
as it seems to be impossible to remove things there :-(
https://unix.stackexchange.com/questions/463291/how-to-remove-device-id-from-manually-entered-usb-serial-driver
Can it be wiped by reinstalling the kernel? I can do this...

> How well does it work?  Why did the developer choose to use this generic
> driver instead of a real one?
I don't know, I followed the advice in dmesg, which sounds as if it's
not a "real" driver.

Best,
Dmitrii
> 
> > [45460.175905] usb 1-3: generic converter now attached to ttyUSB0
> 
> It is not unknown, seems to bind here, but does it work?
> 
> thanks,
> 
> greg k-h

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