Scrolling with touchpad on MacBook Pro 5,5 too sensitive

[MadEgg]

It seems I'm experiencing the following bugs:

https://bugs.kde.org/show_bug.cgi?id=337190
https://bugs.kde.org/show_bug.cgi?id=331706

Scrolling is way too sensitive, even when put on the maximum of 10mm. According to the bug in the KDE bug tracker, this is due to a misreport of the resolution of the touchpad, which has been fixed in a newer version of KDE.

Any clue on how I could go about fixing this? The touchpad has worked fine in Ubuntu 12.04 but I recently switched to Kubuntu 14.04 and the scrolling facility of my touchpad has basically become unusable due to this problem: it's going extremely fast and it's very hard to make sufficiently small movements to scroll at a decent speed. Thanks for any suggestions!

[kubicle]

First, just to make sure you are suffering from a bad resolution on your touchpad, post the output of:
xinput list-props ID# (where "ID#" is the device id number for your touchpad device...you can find the correct device id number by first running xinput)

[MadEgg]

The output of this command is:

Device 'bcm5974':
Device Enabled (142): 1
Coordinate Transformation Matrix (144): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
Device Accel Profile (269): 1
Device Accel Constant Deceleration (270): 2.500000
Device Accel Adaptive Deceleration (271): 1.000000
Device Accel Velocity Scaling (272): 12.500000
Synaptics Edges (273): -3642, 4348, 500, 6125
Synaptics Finger (274): 70, 75, 0
Synaptics Tap Time (275): 180
Synaptics Tap Move (276): 20
Synaptics Tap Durations (277): 180, 180, 100
Synaptics ClickPad (278): 1
Synaptics Middle Button Timeout (279): 0
Synaptics Two-Finger Pressure (280): 283
Synaptics Two-Finger Width (281): 7
Synaptics Scrolling Distance (282): 10, 10
Synaptics Edge Scrolling (283): 0, 0, 0
Synaptics Two-Finger Scrolling (284): 1, 1
Synaptics Move Speed (285): 1.000000, 1.750000, 0.024167, 0.000000
Synaptics Off (286): 2
Synaptics Locked Drags (287): 0
Synaptics Locked Drags Timeout (288): 5000
Synaptics Tap Action (289): 0, 0, 0, 0, 0, 0, 0
Synaptics Click Action (290): 1, 3, 0
Synaptics Circular Scrolling (291): 0
Synaptics Circular Scrolling Distance (292): 0.100007
Synaptics Circular Scrolling Trigger (293): 0
Synaptics Circular Pad (294): 0
Synaptics Palm Detection (295): 0
Synaptics Palm Dimensions (296): 10, 200
Synaptics Coasting Speed (297): 20.000000, 62.730000
Synaptics Pressure Motion (298): 35, 160
Synaptics Pressure Motion Factor (299): 1.000000, 1.000000
Synaptics Resolution Detect (300): 1
Synaptics Grab Event Device (301): 1
Synaptics Gestures (302): 0
Synaptics Capabilities (303): 1, 0, 0, 1, 1, 1, 1
Synaptics Pad Resolution (304): 1, 1
Synaptics Area (305): 0, 0, 0, 0
Synaptics Soft Button Areas (306): 0, 0, 0, 0, 0, 0, 0, 0
Synaptics Noise Cancellation (307): 38, 27
Device Product ID (259): 1452, 566
Device Node (260): "/dev/input/event8"

It states the resolution as being 1 and as I read in that bug report, this is not a correct value.

[kubicle]

Synaptics Pad Resolution (304): 1, 1

Yeah, that doesn't look right, you can try forcing a sensible resolution:

1. Open /usr/share/X11/xorg.conf.d/50-synaptics.conf for editing:
kdesudo kate /usr/share/X11/xorg.conf.d/50-synaptics.conf

2. Add horizontal and vertical resolution options, the examples are for a touchpad that is 70mm wide and 45mm tall (note that it easy to mix up the X and Y values looking at the option names)

Section "InputClass"
Identifier "touchpad catchall"
Driver "synaptics"
MatchIsTouchpad "on"
# This option is recommend on all Linux systems using evdev, but cannot be
# enabled by default. See the following link for details:
# http://who-t.blogspot.com/2010/11/ho...on-errors.html
MatchDevicePath "/dev/input/event*"
Option "VertResolution" "70"
Option "HorizResolution" "45"
EndSection

3. Save the file as /etc/X11/xorg.conf.d/50-synaptics.conf (make the xorg.conf.d -directory if it doesn't exist, and don't save to /usr/share... as the edit will get overwritten on upgrades if you do not save to /etc...)

4. Restart the X server (or reboot)...and verify that the "Synaptics Pad Resolution" values now match your edit.

5. Open SystemSettings touchpad configuration and find scroll distance settings that feel confortable.

[MadEgg]

That works! Great! I've managed to set the scrolling speed to comfortable values using your suggestions. Thanks a lot!