Hej!

I'm developing a custom usb device driver (Stereovision HMD). Unfortunately the Linux usbhid driver (resp. the correlating kernel module) kind of catches the device as soon as it is connected to dhe usb host controller. Thus my own driver (identifying via vendorID and productID) is blocked. I searched the internet for a way to prevent usbhid from catching the device and found a couple of solutions, but nothing worked so far, as I just didn't find the files proposed by that solutions (blacklisting vendorid and productid in some files, e.g. usbhid.conf...). I can't figure out a up-to-date solution.

I'm running Ubuntu, 2.6.32-25 Kernel.

I just can't imagine why the standard Linux driver for HID (usbhid) is associated to that device when there is a driver loaded (my driver kernel module), which provides the correct IDs!? Anyway, is there a solution for that problem? A kind of priority list? Can I override/overload usbhid? Or do I have to use blacklists? Best solution would be within my driver code, as I want to port my driver to other systems whithout hacking some kernel properties everytime...

every hint would be appreciated!

best regards

ps: my nasty workaround is a shell script that unloads the usbhid module, waits 20 seconds for me to plug the usb device and reloads the usbhid module. works. kind of

Can you unbind the USB device from usbhid?

cat xxx > /sys/bus/usb/drivers/usbhid/unbind

Where xxx is its USB ID (this will be a symlink in that directory)

Cheers, Steve

I tried the unbind but got a <permission denied>, even as sudoer :/
I wont get more permissions at this computer...

Any other ideas?

cat xxx > /sys/bus/usb/drivers/usbhid/unbind

Sorry, the cat should be an echo

Steve

hej, tried it with echo:
echo 4-3.1\:1.0 > /sys/bus/usb/drivers/usbhid/unbind

but output is the same, permission denied, with sudo as well.

4-3.1:1.0 should be the correct id. I obtained it with plugging/unplugging the device and searched for changes in /sys/bus/usb/drivers/usbhid/. Is there a nicer way of getting that id? via lsusb, usb-device or via the device-file?

edit:
funny thing: running the script:
#!/bin/bash
modprobe -r usbhid z800_a
modprobe z800_a
modprobe usbhid

, where z800_a is my driver, will load the correct driver for the device even when plugging/unplugging the device. so the sequence in which modules are loaded somehow affect their priority concerning probing devices...?!

When the USB device is bound to the usbhid driver, it should appear as a symlink in the usbhid sysfs directory. For example, my /sys/bus/usb/drivers/usbhid directory looks like this:

2-3:1.0 bind module new_id remove_id uevent unbind

In this case 2-3:1.0 is my mouse.

As root I can echo 2-3:1.0 > unbind and I lose my mouse. The 2-3:1.0 symlink disappears as it's no longer bound to the hid driver. Then I can echo 2-3:1.0 > bind and I get it back again.

I have an FTDI USB serial device which I communicate with using libusb, not through the usb-serial FTDI driver. I have to unbind this one device from the usb-serial driver in exactly the same way.

Cheers, Steve

hej,

yep, it does appear in the usbhid directory. But allt he same even as root I'm somehow not allowed to unbind it this way. but anyway, this is not the solution I'm looking forward, as I want the device to be bound to the correct driver automatically, at startup and without running a script every time...

thanks anyway

I think that I encountered the same problem, and the solution was to add an entry to the hid_ignore_list array in drivers/hid/hid-core.c

See http://permalink.gmane.org/gmane.lin....general/65613

Sorry for reviving an old thread, but I think the reason you're not able to unbind the device is that only the echo is being run as root when using sudo.
Switch to an actual root prompt (sudo -s) first and echoing the device id to the bind/unbind interface should work.

Yes, that does the trick.