Re: Touchpad problems with 2.6.11-rc2

[Dmitry Torokhov]

On Wed, 2 Feb 2005 11:20:33 +0100, Vojtech Pavlik <vojtech@xxxxxxx> wrote:
> On Tue, Feb 01, 2005 at 11:41:48PM -0800, Pete Zaitcev wrote:
> > On 30 Jan 2005 12:10:34 +0100, Peter Osterlund <petero2@xxxxxxxxx> wrote:
> >
> > > > - Slow motion of finger produces no motion, then a jump. So, it's very hard to
> > > >   target smaller UI elements and some web links.
> > >
> > > I see this too when I don't use the X touchpad driver. With the X
> > > driver there is no problem. I think the problem is that mousedev.c in
> > > the kernel has to use integer arithmetic, so probably small movements
> > > are rounded off to 0. I'll try to come up with a fix for this.
> >
> > Thanks for the hint. I tried various schemes and mathematical transformations
> > and found one which gives unquestionably the best result, with smoothest, most
> > precise and comfortable pointer movement:
> 
> Well, you removed the scaling to the touchpad resolution, which will
> cause ALPS touchpad to be significantly slower than Synaptics touchpads.

Yep, Synaptics I think has 4-5x higher resolution.

> Similarly, the screen size used to be taken into account, but probably
> that was a mistake, since the value is usually left at default and
> doesn't correspond to the real screen size.

I wonder if we should just add speed factor (along with tap distance)
options to mousedev. Vojtech, will you take such patch? I know you
want to drop mousedev and have everyone use evdev but, although people
started switching, it will not happen until distributions (or
XOrg/XFree themselves) have these drivers available straight out of
the box.

-- 
Dmitry
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