Logitech ps2++ scroll wheel + KVM fix (sort of)

I've found a fix for a problem I was having with the combination
of my Logitech trackball's scrollwheel and my KVM switch. My scroll wheel would work until I switched away from my Linux desktop; after switching back, the evbug module reported no events when turning the wheel.

According to Belkin, this is because my KVM switch does not
support the Logitech protocol, only the MS Intellimouse one. I noticed that WinXP had no such problems, so I commented out the section in psmouse_extensions() that detected Logitech mice. Now my trackball is detected as a "ImPS/2 Generic Wheel Mouse" and the scroll wheel always works.

It would be good to have a parameter that would allow me to force
this mouse to use the ImPS/2 protocol rather than the logitech PS2++; I probably won't be the last person to have this kind of problem (which I didn't have with 2.4).

The following patch makes that parameter: psmouse_imps2. Will you
consider it applying it, or something like it?

diff -urN linux-2.6.0-test1/Documentation/kernel-parameters.txt linux-2.6.0-test1-changed/Documentation/kernel-parameters.txt
@@ -780,6 +780,8 @@
 
 	psmouse_noext	[HW,MOUSE] Disable probing for PS2 mouse protocol extensions
 
+	psmouse_imps2	[HW,MOUSE] Probe only for Intellimouse PS2 mouse protocol extensions
+
 	pss=		[HW,OSS] Personal Sound System (ECHO ESC614)
 			Format: <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
 

Joseph Fannin
[email protected]

"Bull in pure form is rare; there is usually some contamination by data."
    -- William Graves Perry Jr.