Preventing usbhid from claiming device

1
votes

In order for my USB driver's _probe function to be called, I need to prevent usbhid from claiming it first. To do this I wrote a UDEV rule which unbinds the device.

SUBSYSTEM=="usb", DRIVER=="usbhid", ATTRS{idVendor}=="ffff", ATTRS{idProduct}=="ffff", RUN="/bin/sh -c 'echo -n $id:1.0 > /sys/bus/usb/drivers/usbhid/unbind'"

While this works, what is the standard practice for distributing drivers? Do I have to also package this rule? Is there any way for my own driver to take priority over usbhid?

1
linuxdriversusbpackaging
Since this is more of a driver programming question, it might be better placed on Stack Overflow, or in a hardware_development.SE if one exists. – telcoM

1 Answers

0
votes

The kernel selects the drivers for each device based on the MODULE_DEVICE_TABLEs. The HID device table is considered more specific than the generic USB device table, so if your device claims USB HID device class, then your driver should probably include a HID class MODULE_DEVICE_TABLE too.

The matching algorithm favors specific matches over generic class-based ones, so if your device table entry includes some USB or HID device attributes unique to it, your driver should get priority over the generic usbhid driver.

If your idVendor and idProduct identifiers are actually both 0xffff, then I guess you're dealing with a prototype device that does not yet have proper USB vendor/device identifiers. You'll want to fix that.