I've just switched from Xorg to Wayland, which means I've also switched to libinput. I'm also using GNOME 3 and GDM.
Since switching, scrolling has become very jumpy. As I drag two fingers vertically across the touchpad as slowly as possible and pausing periodically as I go, after a certain distance it will "jump".
This doesn't happen in all applications; I'm guessing anything running in Xwayland doesn't have the issue. Such applications still scroll and accelerate faster than I'd like, but I assume that's a separate issue.
The problem occurs in both GTK+ and Qt applications.
For example, when scrolling in gedit, which supports smooth scrolling:
- Start on line 1
- Scroll smoothly until line 5
- As soon as I hit line 5, no matter how slowly I'm scrolling, it jumps to line 10.
- Scroll back up toward line 1, going smoothly until line 5
- At line 5, jumps to line 1
The jump always happens 5 lines from where I start scrolling. If I stop scrolling but leave both of my fingers on the touchpad, it doesn't actually count as stopping.
I have a Synaptics touchpad on a Yoga 900:
Device: SYNA2B29:00 06CB:77C6 Kernel: /dev/input/event14 Group: 5 Seat: seat0, default Size: 91.53x59.95mm Capabilities: pointer Tap-to-click: disabled Tap drag lock: disabled Left-handed: disabled Nat.scrolling: disabled Middle emulation: n/a Calibration: n/a Scroll methods: *two-finger edge Click methods: *button-areas clickfinger Disable-w-typing: enabled Accel profiles: none
I'm running Linux 4.4 with some driver patches I stole from 4.5 to get the hardware on the Yoga 900 working properly. Up-to-date Arch Linux with testing repository enabled (core is still on 4.3, but 4.4 has patches that I need).
linux-custom 4.4-4 libinput 1.1.4-1 wayland 1.9.0-1 gnome-shell 3.18.3-2 xorg-server-xwayland 1.18.0-4
I'm at a bit of a loss for how to troubleshoot this because so many factors are involved, and I'm unfamiliar with libinput and Wayland. I switched to Wayland because X was having trouble with my high-PPI display in many cases. Wayland also seems to better utilize my CPU's integrated graphics. So for now, I'd like to stick with Wayland, even if I can't find an immediate solution. I'd prefer to solve this on my own (via patches, hacks, whatever) rather than wait for a proper fix to be developed, tested, and released.