Re: Touchpad problems with 2.6.11-rc2

[Vojtech Pavlik <vojtech@suse.cz>]

On Fri, Feb 04, 2005 at 07:40:43AM +0100, Peter Osterlund wrote:
> Vojtech Pavlik <vojtech@suse.cz> writes:
> 
> > On Thu, Feb 03, 2005 at 10:54:51PM +0100, Peter Osterlund wrote:
> > 
> > > * Removes the xres/yres scaling so that you get the same speed in the
> > >   X and Y directions even if your screen is not square.
> > 
> > The old code assumed that both the pad and the screen are 4:3, not
> > square. It was wrong still.

> alps.c currently contains:
> 
> 	psmouse->dev.evbit[LONG(EV_ABS)] |= BIT(EV_ABS);
> 	input_set_abs_params(&psmouse->dev, ABS_X, 0, 1023, 0, 0);
> 	input_set_abs_params(&psmouse->dev, ABS_Y, 0, 1023, 0, 0);
> 	input_set_abs_params(&psmouse->dev, ABS_PRESSURE, 0, 127, 0, 0);
> 
> Maybe it should set the ABS_Y max value to 767 in that case.

Yes, and no. It could have been 1023, if it was 3:4 in size, but not in
maximum values. See the real values below, though, it seems the
resolution in X and Y is indeed the same.

> --- linux/drivers/input/mouse/alps.c~	2005-01-12 22:02:19.000000000 +0100
> +++ linux/drivers/input/mouse/alps.c	2005-02-04 07:38:12.203436768 +0100
> @@ -394,7 +394,7 @@
>  
>  	psmouse->dev.evbit[LONG(EV_ABS)] |= BIT(EV_ABS);
>  	input_set_abs_params(&psmouse->dev, ABS_X, 0, 1023, 0, 0);
> -	input_set_abs_params(&psmouse->dev, ABS_Y, 0, 1023, 0, 0);
> +	input_set_abs_params(&psmouse->dev, ABS_Y, 0, 767, 0, 0);
>  	input_set_abs_params(&psmouse->dev, ABS_PRESSURE, 0, 127, 0, 0);
>  
>  	psmouse->dev.keybit[LONG(BTN_TOUCH)] |= BIT(BTN_TOUCH);
 
My ALPS gives values:

	X: 90-1019
	Y: 100-749
 Pressure: 0,34-108

So 0-1024, 0-768, 0-127 are probably the maximum theoretical ranges, and
the rest are likely the mechanical mounting limitations of the notebook
(the ridge around the pad is not rectangular).

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR