Bug 53936

Kubuntu 12.10 quantal alpha 3 (amd64), xserver-xorg-input-synaptics package is version 1.6.2-1ubuntu4, kernel is 3.5.0-11-generic, both from the main repo. The machine is a Dell Latitude E6520 and xinput reports its touchpad as an Alps.

I recently wiped my 12.04 system, installed 12.10a3 fresh, and promptly noticed that edge-scrolling wasn't working anymore. It turns out the calculated physical pad dimensions is off by just enough to put the edges out of reach.

Xorg.0.log bits;
>synaptics: AlpsPS/2 ALPS DualPoint TouchPad: x-axis range 0 - 2000
>synaptics: AlpsPS/2 ALPS DualPoint TouchPad: y-axis range 0 - 1400
>synaptics: AlpsPS/2 ALPS DualPoint TouchPad: Vendor 0x2 Product 0x9

...and the sysfs entries in /sys/class/input/input*/id agree;
>bustype 0011
>product 0009
>vendor  0002
>version 7326

Dimensions as reported by xinput list-props;
>Synaptics Edges (306):  80, 1920, 75, 1325

Dimensions from whatever driver version I was running at 120320 (distro then was likely 12.04b, whose current package version is now 1.5.99.902-0ubuntu5 for comparison);
>Synaptics Edges (280):  300, 1700, 210, 1190

The numbers make sense if priv->MODEL != MODEL_ALPS (synaptics.c:298).

MODEL_ALPS edge modifiers: width 0.15, height 0.15
>2000 * 0.15 = 300
>1400 * 0.15 = 210
Generic edge modifiers: width .04, height 0.54
>2000 * 0.04  = 80
>1400 * 0.054 = 75.6


There are several factors here (new kernel, new xorg, new synaptics driver, new udev, even new BIOS but unsure how that affects touchpad vendor/product id), so this may just be a NOTOURBUG.

Let me know what else I can do to troubleshoot.