Bug 100752

Summary: Cursor lag on synaptics touchpad
Product: Wayland Reporter: Luis Pabon <copong>
Component: libinputAssignee: Wayland bug list <wayland-bugs>
Status: RESOLVED DUPLICATE QA Contact:
Severity: normal    
Priority: medium CC: convulsingjaggies, daniel.van.vugt, peter.hutterer
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Bug Depends on:    
Bug Blocks: 98535    
Attachments: evemu-record /dev/input/event5
/sys/class/dmi/id/modalias
udevadm info /sys/class/input/event5

Description Luis Pabon 2017-04-21 11:54:19 UTC
Created attachment 130963 [details]
evemu-record /dev/input/event5

I'm currently trialling Gnome 3.24 on Ubuntu 17.04 and Wayland. I find libinput to work really well on my mouse, but the touchpad seems to have some input lag (can't quite quantify how much, maybe 100ms), just about enough to throw me off when trying to reach stuff like buttons, links, window borders etc. Essentially I always overshoot. This doesn't seem to happen with the mouse, as said earlier.

I'm attaching the required diagnostic dumps below.

Ubuntu 17.04, libinput10 1.6.3-1ubuntu1 amd64, libwayland-(bin|client0|cursor0) 1.12.0-1 amd64.
Laptop is a Fujitsu A544.
Comment 1 Luis Pabon 2017-04-21 11:55:03 UTC
Created attachment 130964 [details]
/sys/class/dmi/id/modalias
Comment 2 Luis Pabon 2017-04-21 11:55:42 UTC
Created attachment 130965 [details]
udevadm info /sys/class/input/event5
Comment 3 Luis Pabon 2017-04-21 11:57:50 UTC
I forgot to add, touchpad dimensions are 109x70mm
Comment 4 Luis Pabon 2017-04-21 11:59:58 UTC
Also, kernel 4.10.0-19-generic #21-Ubuntu SMP
Comment 5 Peter Hutterer 2017-04-24 05:19:18 UTC
I'm going to assume that this is this gnome issue:
https://bugzilla.gnome.org/show_bug.cgi?id=745032
Comment 6 Peter Hutterer 2017-04-24 05:19:47 UTC
*** Bug 100705 has been marked as a duplicate of this bug. ***
Comment 7 Luis Pabon 2017-04-24 09:38:38 UTC
Peter, it's not the same problem at all.
Comment 8 Peter Hutterer 2017-04-25 00:56:03 UTC
hmm, true, sorry, didn't read properly. If you debug this with the in-tree event-gui, do you still see the issue there? Just trying to rule out any userspace stuff.

Is this something new, i.e. did it work better with previous libinput versions, or previous wayland versions, or did it work with the same libinput under Xorg?
Comment 9 Luis Pabon 2017-04-25 09:53:23 UTC
This is the first time I've used both Wayland or libinput at all I'm afraid, I belong to the hordes of panicking Unity users looking about for an alternative.

I'll come back shortly after I test separately wayland/libinput on event-gui and x/libinput.
Comment 10 Peter Hutterer 2017-05-19 05:36:18 UTC
any updates?
Comment 11 Luis Pabon 2017-05-19 09:30:48 UTC
Apologies Peter, I just came back yesterday from annual leave. I'll try run these tests over the weekend and report back.
Comment 12 Luis Pabon 2017-05-21 15:55:09 UTC
Peter,

I've switched X to use libinput and tested about on Unity, Gnome and XFCE for good measure. There's no lag to speak of with these combinations. It seems to be restricted to wayland + libinput.
Comment 13 Peter Hutterer 2017-05-22 00:18:39 UTC
You did use the xf86-input-libinput driver under xorg, did you? Because if so, then that would indicate a gnome bug, possibly https://bugzilla.gnome.org/show_bug.cgi?id=745032
Comment 14 Peter Hutterer 2017-06-26 09:45:43 UTC
ping?
Comment 15 Luis Pabon 2017-06-26 10:30:08 UTC
Hi Peter,

Yes, indeed using the xserver-xorg-input-libinput driver in X. That's definitely not the same bug. I'm experiencing no jerkiness or otherwise in touchpad action, only a slight lag and only on the touchpad - indeed, if I simply reach for the mouse that works fine.
Comment 16 Peter Hutterer 2018-01-09 04:05:20 UTC
Any chance you can try the latest libinput (1.9.4). That has the hysteresis removed and should provide more responsive slow motion.
Comment 17 Daniel van Vugt 2018-01-10 08:19:24 UTC
Duplicate of bug 98839.

Not having enough precision to "reach stuff like buttons, links, window borders etc" is fixed with bug 98839, due for release in libinput 1.10.
Comment 18 Peter Hutterer 2018-03-06 04:32:42 UTC
Closing as dupe of 98839, note that while some patches are in 1.10, there are extra fixes on master to improve that, specifically 6936a1555 and 400aadd53ac0.

*** This bug has been marked as a duplicate of bug 98839 ***

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