Re: synaptics mouse jitter in 2.6.0

[Dmitry Torokhov <dtor_core@ameritech.net>]

On Monday 22 December 2003 09:40 pm, Thomas Molina wrote:
> I am running Fedora Core 1 updated on a Presario 12XL325 laptop.  For a
> long time during the 2.5 series I couldn't use the synaptics support. 
> As a result, I haven't tested this for some time.  I just compiled a
> fresh 2.6.0 tree, included synaptics support and now I am getting mouse
> jitter.
>
> The easiest way to see this is to open Mozilla and go to a page with a
> lot of text links such as a news site with links to a number of
> stories. With synaptics support compiled in I get side to side jitter
> when moving the mouse over a link.  It looks as if my finger has a
> nervous twitch in it.  Then, when I take my finger off the touchpad to
> click on the link, the mouse cursor jumps about an eighth of an inch in
> a random direction.  It is very annoying since the jump takes it off
> the link and I can't click on it.
>
> Compiling synaptics support out gets me back to a stable mouse cursor.

Right, I think I see it. The mousedev module does not do any smoothing
of the reported coordinates which would cause the jitter you are seeing.
Normally drivers do 3- or 4-point average.

I'll cook up something to fix it. Meanwhile could you give a try Peter
Osterlund XFree86 Synaptics driver:
http://w1.894.telia.com/~u89404340/touchpad/index.html

Dmitry