Re: Really annoying bug in the mouse driver

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Wed, 02 Feb 2005 11:22:43 +0100, Victor Hahn <victorhahn@web.de> wrote:
> Dmitry Torokhov wrote:
> 
> >It still complains in dmesg about throwing away bytes, right? Please try
> >loading the box some more to make sure mouse survives some abuse.
> >
> >
> 
> No, it doesn't. The only message I still get is the one below. I've
> tried it with aprox. 90% CPU usage already and I didn't have any
> additional problems.
>

Processor load we usually handle well, loaded disks are usually the
ones that cause >= 0.5 sec delays between bytes received by psmouse.
Please let me know if it still works with busy disks.

> >>kernel: psmouse.c: bad data from KBC - bad parity
> >>
> >>
> >Your keyboard controller reported that the byte transmitted from the mouse
> >was mangled somehow and we should not trust it. I am not sure why it would
> >make mouse jump.. was there any mention of "reconnect" in the logs? Did it
> >happen just once?
> >
> 
> It happened once when I was at the computer and several times while I
> wasn't.

Well, we won't be able to do anythng about parity errors themselves
but hopefully the patch will make them almost invisible for you. I
wonder if the jump could be explained by having a byte with 2 bits
flipped. KBC then would not detect parity error and psmouse would
process the byte as if it was good. This should not be happening too
often.

> There's no "reconnect" in the logs:
> 
> victor@vic:~$ cat /var/log/messages | grep reconnect
> victor@vic:~$

Ok, I was wondering if you hit parity error twice in a row and it
decided to reconnect.

-- 
Dmitry