[natty] two-finger-scroll stopped working after today's update

[Ярослав Почернин]

Having installed the lates utouch updates I found myself unable to use two-finger-scroll on my Toshiba NB100. It used to work in Natty up to this point. The "cat /proc/bus/input/devices" lines for my touchpad are:

I: Bus=0011 Vendor=0002 Product=0007 Version=01b1
N: Name="SynPS/2 Synaptics TouchPad"
P: Phys=isa0060/serio4/input0
S: Sysfs=/devices/platform/i8042/serio4/input/input6
U: Uniq=
H: Handlers=mouse0 event6
B: PROP=1
B: EV=b
B: KEY=420 0 30000 0 0 0 0 0 0 0 0
B: ABS=11000003

[Chase Douglas (chasedouglas)]

This is likely a consequence of bug 742213. Your touchpad can give only pressure information, but pressure data is not reliable enough to be used by out of the box. For a while, Natty used the pressure data by default, but this has been reverted due to a report of spurious right click behavior.

You can restore the previous functionality in two ways:

1. At runtime by running: "xinput set-prop 'SynPS/2 Synaptics TouchPad' 'Synaptics Two-Finger Pressure' 29
2. At X startup by putting the following in your /etc/X11/xorg.conf (create it if it doesn't exist):

Section "InputClass"
        Identifier "touchpad catchall with default scroll"
        Driver "synaptics"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
        Option "EmulateTwoFingerMinZ" "29"
EndSection

Because this is the intended result of the change to synaptics, I'm marking this as "won't fix".

[Eric Appleman (erappleman)]

Please revert those needless changes.

I: Bus=0011 Vendor=0002 Product=0007 Version=01b1
N: Name="SynPS/2 Synaptics TouchPad"
P: Phys=isa0060/serio1/input0
S: Sysfs=/devices/platform/i8042/serio1/input/input7
U: Uniq=
H: Handlers=mouse1 event7
B: PROP=1
B: EV=b
B: KEY=420 0 30000 0 0 0 0 0 0 0 0
B: ABS=11000003

[Chase Douglas (chasedouglas)]

Hi Eric,

Enabling two touch actions, such as scrolling and right clicking, by default for these trackpads was a new addition to synaptics in Natty. However, we noticed that it caused a regression when the default values were not reasonable for some devices. In the upstream synaptics input module project, the change has already been reverted, just like we have done in Natty.

I am sorry that this is an inconvenience for you, but you may follow the steps outlined in comment #1 to restore the functionality you had. Unfortunately, it's the best we can do under the circumstances.

One resolution to this issue may be to add an option to the mouse preferences to use pressure for two finger actions, but this should be developed upstream in the Gnome project first.