Strange mouse behaviour after switching to evdev.

[Peter Hutterer]

On Sun, Jun 21, 2009 at 10:40:55PM +0200, Łukasz Maśko wrote:
> I have a Kensington SlimBlade BlueTooth mouse and I use it with my laptop. 
> So far, I've used it with a mouse driver and had no problems - only 
> left-right scrolling didn't work. Recently I've switched to evdev just to 
> give it a try. Well... it works. Evdev recognizes all the buttons, even 
> left-right scrolling works. But I'm noticing one strange behaviour - from 
> time to time, ocasionally, the mouse pointer suddenly moves to the point 
> (0,0), to the very left-top corner. Just like that, without any reason - I 
> don't even touch my mouse. There are no reports in log files about these 
> events. I had no such behaviour with mouse driver.

http://people.freedesktop.org/~whot/evtest.c
run this against the mouse's device file (/dev/input/eventX, check in
/proc/bus/input/devices for the number) and leave it running. 

right after the mouse jumps, check the last events in the log it spits out.
Is there anything weird? if it's caused by the kernel/hardware then you
should see the jump as a large movement. if not, then it's somewhere in the
driver or (more likely) the server.

Cheers,
  Peter