[libhid-discuss] example program kills hiddev device node

[Peter Stuge]

On Sun, Nov 11, 2007 at 10:17:03PM +0100, Tino Keitel wrote:
> It seems like hid_force_open() kills the device

Quite correct.


> Anyone knows what's going on here, and how to fix it?

The hiddev device nodes are provided by the kernel HID driver.

hid_force_open() detaches the kernel HID driver so that libhid can
communicate directly with the device through usbfs, which is
impossible if another kernel driver is attached to the device.

There's no simple fix if the app uses libhid.

Difficult fixes include:
1. changing the app to use the hiddev API when possible
2. changing libhid to use the hiddev API when possible

Myself and others have thought about 2 for some time, but haven't
found time to do it. I've also heard rumors that hiddev will be
replaced, which means it may be even less likely to happen sooner
rather than later.


//Peter