1741613 - [wayland] Visual stutter when scrolling with touchpad

Status: RESOLVED DUPLICATE of bug 1744896

(Core :: Widget: Gtk, defect, P3)

Description

[Andrew]

Attachment: Screengrab

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

Compositing: WebRender
Window Protocol: wayland
Desktop Environment: gnome 41

Assume a static and fully loaded webpage. I scroll it with a touchpad through a two-finger scrolling gesture.

Actual results:

When I'm scrolling it with a touchpad, moving my fingers with consistent speed produces some noticeable stutter in page movements. However, if I release fingers (thus ending the gesture) and let it glide (e.g. engaging fling scrolling), then the stutter disappears. Moreover, if I start to scroll it again with a touchpad before it stops, effectively «picking up» ongoing fling scrolling, then moving my fingers with consistent speed no longer produces any stuttering.

This happens irrelevant of what scaling governor is in use (e.g. performance / powersave).

The effect is demonstrated twice in the attached screengrab.

Mozregression gave me following pushlog:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=334e3d59d932dd2850dec7c582f32f49b504e450&tochange=f632271e9d62ad6b7e90acd52e77d3e02a66980e

Moreover, I double-checked Nightly from 2021-10-24 and it indeed works perfectly and doesn't exhibit stuttering at all.

Expected results:

No noticeable stutter during two-finger scrolling.

Comment 1

[Andrew]

Attachment: about.support

about:support raw data

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Gtk' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 3

[Martin Stránský [:stransky] (ni? me)]

Robert, any idea?

Comment 4

[Martin Stránský [:stransky] (ni? me)]

Should be duplicate of Bug 1744896.