Switchbox + mouse = braindead mouse?

Switchbox + mouse = braindead mouse?

Post by Phil Howa » Fri, 09 Apr 1999 04:00:00

| I have a belkin switchbox connected up to a
| linux box.  Occasionally (rare) when switching
| to the linux box, my mouse goes brain dead.
| The *only* solution to recover from this state
| is to reboot the box.

If gpm has the mouse open, just kill and restart gpm.

| Having written MS-mouse drivers before *and*
| looking at the kernel source, I think I know
| what the problem is.
| I hesitate to make any changes to the kernel
| unless I can (reliably) reproduce the problem
| to test.  As stated, this only occurs "rarely"
| on my box and I cannot reproduce it "on demand"
| 1.  Has anyone else experienced this problem?
| 2.  Does anyone know how to reliably reproduce
| the problem?

I get this problem at times, with and without a box.  The times
without a box are when I get up from my chair, which is a vinyl
covered pad kind of thing, and get a static charge.  It discharges
into the frame of the chair and poses no danger to the computer
(as long as I make sure I discharge it only into the chair) but
many times, the discharge does seem to get into the long mouse
cord.  What appears to be happening is that the bit shifter in
the serial connection via my AUX/PS2 port gets into some weird
state due to the spurious bits.  Subsequent moving of the mouse
does not flush out this state, so it's not entirely clear that
is is merely a single extra bit.  However, killing and restarting
gpm does fix it.  It may be that gpm is hosed.

I do have X getting its mouse movements via gpm, so when I fix
gpm, it fixes X.  If you have them sharing the device, you may
have to restart X to fix it, so I'd recommend having X get mouse
movements from gpm if indeed restarting gpm fixes your case.

| If you know how to reliably reproduce the problem,
| please post your reply AND email it to me.

I don't know that what I do is exactly your problem or not.

Phil Howard           KA9WGN