GNOME Bugzilla – Bug 751618
Mouse pointer gets accelerated a lot when secondary screen is connected
Last modified: 2015-06-30 18:58:33 UTC
Each time I connect a secondary screen to my laptop, I need to move my touchpad with a lot of care to not "run too much" as its speed looks to be increased a lot when that screen is not connected. Personally I don't understand why we need to get the mouse with this increased speed, exactly as the speed doesn't change when I have a 15" single screen or a 24" one. Thanks a lot
We don't change speed in gnome-control-center, nor in gnome-settings-daemon in relation with screens. You can simply prove that the speed is still same in gsettings when you connect the external screen by the following command: gsettings get org.gnome.desktop.peripherals.touchpad speed I suppose the problem is in mutter, or libinput. I think there might be problems with hidpi, or libinput might have some heuristics based on screen size... Peter, do you have an idea what is wrong?
You are true, gsettings outputs the same even if it's clear that something occurs with the mouse as it starts to move much faster when I connect the TV via HDMI :( $ gsettings get org.gnome.desktop.peripherals.touchpad speed 0.0
Mutter is where the configuration is applied. That doesn't mean the problem isn't really in the X11 libinput driver, but the problem isn't gnome-control-center as the configuration doesn't change.
Pacho: which driver do you use? synaptics or libinput? synaptics had this problem for a while now, see https://bugs.freedesktop.org/show_bug.cgi?id=83114 libinput should not be affected by this though, it doesn't use the screen size for relative coordinates.
I am using synaptics driver 1.8.1 indeed :/ Thanks for pointing to the right culprit ;)
*** This bug has been marked as a duplicate of bug 707616 ***