Re: 2.5.44: Still has KVM + Mouse issues

Vojtech Pavlik (vojtech@suse.cz)
Mon, 28 Oct 2002 18:34:19 +0100


On Fri, Oct 25, 2002 at 06:57:24PM -0500, Jon Grimm wrote:
> Hello,
> I see that Thomas Molina 2.5 problem list no longer carries a KVM and
> mouse
> issue where it previously had.
>
> If a fix is available I'd love to test it out as I still see strange
> behavior
> with an Intellimouse and my MasterView CS-104 KVM switch (yep its
> old).
>
> With a few trusty printks, it looks like after I switch away & back
> into 2.5.44, the mouse is now sending 3 byte packets instead of the 4 it
> previously was.
>
> As you can imagine this causes all sorts of havok as the packets are
> interpretted completely wrong from there on out. If there is enough
> delay between
> events, the synchonization logic kicks in and throws the packet out,
> since
> it thinks the 4th byte is old (where it is really the first byte of the
> next
> 3-byte packet). This generates those pesky "psmouse.c: Lost
> synchronization "..
> However, much of the time an incorrect 4-byte frame gets interpretted
> and
> the X going totally haywire.
>
> BTW, serio_rescan() gets the mouse back into a happy 4-byte generating
> state.

The workaround is to use "psmouse_noext" command line parameter in case
you use a KVM switch that cannot properly handle the extended protocols.

-- 
Vojtech Pavlik
SuSE Labs
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