Re: psmouse: "bad data from KBD - bad parity" every 2ms with synaptics touchpad

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

On Tue, Nov 01, 2011 at 02:34:58PM -0500, Jonathan Nieder wrote:
> Damjan Jovanovic wrote:
> 
> > Maybe that touchpad doesn't send proper parity. See what we did in commit
> > 6b9d363c49d22395d0cf8729c5963f83cfbb6d69, and try to disable parity
> > checking for that touchpad the same way?
> 
> Sure, though it would be nice to understand the problem better first.
> 
> So:
> 
>  - Arvind, could you say a little more about when this started
>    happening[1]?  Did you change your configuration, or was there any
>    upgrade around the same time (/var/log/dpkg.log* should say)?  Any
>    idea why this wasn't always happening from the start?

If this was working and then stopped I'd try removing the keyboard and
cleaning and reseating the touchpad connector.

> 
>  - Others, any idea what information would be useful to track this
>    further?  Are there tools or patches for tracing what the kernel
>    gets told by the touchpad, so we could see the nature of these
>    parity errors?

Booting with i8042.debug=1 or doing
"echo 1 > /sys/module/i8042/parameters/debug" will dump all data from
the keyboard controller to dmesg. It is quite a bit though (80 pps @ 6
bytes/packet).

-- 
Dmitry