evdev driver issue

Aivils Stoss aivils at latnet.lv
Fri Jun 30 00:33:57 PDT 2006

On Piektdiena, 23. Jūnijs 2006 06:47, Vinay Reddy wrote:
> Hi,
> I'm developing an absolute USB mouse (which has 2 absolute axes, for
> one for X and the other for Y and one relative axis for the scroll
> wheel) and I'd like to use the built-in evdev drivers for the mouse.
> The mouse works perfectly fine on Windows, but there seem to be quite
> a few issues with Linux. I'm using X11R7.0 on Ubuntu Dapper Drake.
> When I move the mouse, the cursor jumps around for a while before
> ultimately settling at the right location (during this time the CPU
> utilization goes to 100%). This I feel shouldn't happen as I've logged
> the USB packets in the kernel hid-core.c driver and they seem to be
> perfectly fine (and the values don't jump around). I've also logged
> the values in the evdev driver for X and the values here are fine too.
> I feel that X is receiving junk events from elsewhere, but there are
> no other mice that are connected to the computer.
> Also, when I remove this relative axis in hardware, this jumping
> around is gone, but the mouse seems to be moving only in straight
> lines (when I move it diagonally, it firstly moves in Y and then in
> X). So, the jumping somehow seems to be connected to the relative
> axis...
> Also EvDevCorePreInit (in evdev.c) always fails and returns NULL. The
> evdev X driver ends up calling EVIOCGRAB...
> If any of you have any insight into what's going on, I'd appreciate it
> if you could share it with me...

For testing purposes You can use this one:

It catches kernel events and send to X via XTEST extension.
May be this help You to locate the trouble.

Aivils Stoss

More information about the xorg mailing list