PATCH: PR Input Devives/2082: PS/2 mouse out of sync after switching with KVM switch

PATCH: PR Input Devives/2082: PS/2 mouse out of sync after switching with KVM switch

[H.J. Lu]

The bug report is at

http://bugzilla.kernel.org/show_bug.cgi?id=2082

Problem Description: When switching to another machine with a KVM
switch and back, the mouse is out of control, with X.Org.  To recover,
 I have to unplug the mouse cable and plug it back.

Steps to reproduce: Have a wheel mouse connected and X.Org.  Keyboard,
Mouse and Video are connected to a KVM switch. Switch to another
machine and back.  You have lost the usage of wheel on mouse.

This patch for 2.6.23 tries to reconnect the mouse after KVM switch.
It doesn't completely solve the problem. Mouse still got a few random
bytes after KVM switch. But it recovers with kernel message:

psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, issuing reconnect request.

instead of

psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing 3 bytes away.

and never recovering from it.

BTW, please CC me when reply.  Thanks.


H.J.
----
--- linux-2.6.23.x86_64/drivers/input/mouse/psmouse-base.c.reset	2007-10-09 13:31:38.000000000 -0700
+++ linux-2.6.23.x86_64/drivers/input/mouse/psmouse-base.c	2007-10-26 23:27:55.000000000 -0700
@@ -302,11 +302,11 @@ static irqreturn_t psmouse_interrupt(str
 
 	if (psmouse->state == PSMOUSE_ACTIVATED &&
 	    psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) {
-		printk(KERN_INFO "psmouse.c: %s at %s lost synchronization, throwing %d bytes away.\n",
-		       psmouse->name, psmouse->phys, psmouse->pktcnt);
+		printk(KERN_INFO "psmouse.c: %s at %s lost synchronization, issuing reconnect request.\n",
+		       psmouse->name, psmouse->phys);
 		psmouse->badbyte = psmouse->packet[0];
-		__psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
-		queue_work(kpsmoused_wq, &psmouse->resync_work);
+		__psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+		serio_reconnect(psmouse->ps2dev.serio);
 		goto out;
 	}
 

Re: PATCH: PR Input Devives/2082: PS/2 mouse out of sync after switching with KVM switch

[Dmitry Torokhov]

Hi,

On 10/30/07, H.J. Lu <hjl@lucon.org> wrote:
> The bug report is at
>
> http://bugzilla.kernel.org/show_bug.cgi?id=2082
>
> Problem Description: When switching to another machine with a KVM
> switch and back, the mouse is out of control, with X.Org.  To recover,
>  I have to unplug the mouse cable and plug it back.
>
> Steps to reproduce: Have a wheel mouse connected and X.Org.  Keyboard,
> Mouse and Video are connected to a KVM switch. Switch to another
> machine and back.  You have lost the usage of wheel on mouse.
>
> This patch for 2.6.23 tries to reconnect the mouse after KVM switch.
> It doesn't completely solve the problem. Mouse still got a few random
> bytes after KVM switch.

Have you tried psmouse.resync_time=5 option?

Any change you coudl do

echo 1 > /sys/module/i8042/parameters/debug

before switrching KVM back and forth and send me dmesg?

> But it recovers with kernel message:
>
> psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, issuing reconnect request.
>
> instead of
>
> psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing 3 bytes away.
>
> and never recovering from it.
>

I am hesitant queuing reconnect immediately - if the byte was delayed
because embedded controller was busy doing something else and we start
querying mouse at the wrong time we might lose mouse altogether.

-- 
Dmitry

Re: PATCH: PR Input Devives/2082: PS/2 mouse out of sync after switching with KVM switch

[H.J. Lu]

On Tue, Oct 30, 2007 at 12:53:17PM -0400, Dmitry Torokhov wrote:
> Hi,
> 
> On 10/30/07, H.J. Lu <hjl@lucon.org> wrote:
> > The bug report is at
> >
> > http://bugzilla.kernel.org/show_bug.cgi?id=2082
> >
> > Problem Description: When switching to another machine with a KVM
> > switch and back, the mouse is out of control, with X.Org.  To recover,
> >  I have to unplug the mouse cable and plug it back.
> >
> > Steps to reproduce: Have a wheel mouse connected and X.Org.  Keyboard,
> > Mouse and Video are connected to a KVM switch. Switch to another
> > machine and back.  You have lost the usage of wheel on mouse.
> >
> > This patch for 2.6.23 tries to reconnect the mouse after KVM switch.
> > It doesn't completely solve the problem. Mouse still got a few random
> > bytes after KVM switch.
> 
> Have you tried psmouse.resync_time=5 option?

My psmouse is kernel builtin. I tried "psmouse.proto=imps" and
it worked. But I don't want to change kernel boot option for each
kernel on each machine behind KVM.

> 
> Any change you coudl do
> 
> echo 1 > /sys/module/i8042/parameters/debug
> 
> before switrching KVM back and forth and send me dmesg?

I will try it when I get home.

> 
> > But it recovers with kernel message:
> >
> > psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, issuing reconnect request.
> >
> > instead of
> >
> > psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing 3 bytes away.
> >
> > and never recovering from it.
> >
> 
> I am hesitant queuing reconnect immediately - if the byte was delayed
> because embedded controller was busy doing something else and we start
> querying mouse at the wrong time we might lose mouse altogether.
> 

As it stands now, my Microsoft wheel mouse isn't usable at all after
KVM switch without my patch. I had to reset mouse cable to get it back.


H.J.