1630490 - Vsync cap on 144 hz Multi-monitor Setup & SW VSYNC

Status: UNCONFIRMED

(Core :: Graphics, defect, P3)

Description

[sgl4kn]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux; rv:74.0) Gecko/20100101 Firefox/74.0

Steps to reproduce:

1. Use a primary monitor with 144Hz (Freesync enabled) & a secondary monitor with 60Hz (an audio Hifi receiver in my case)
2. Clone the desktop
3. Start FF on the primary monitor and open testufo.com

Actual results:

Framerate is locked at 60Hz. Trying to enforce it via layout.frame_rate=144 crashes FF on Windows. If included in the pref.js it takes the setting, but is still just using 60Hz on testufo (or on the internal gfx.webrender.debug.profiler = true).

Expected results:

1. FF should use the maximum framerate of connected monitors
2. If that's not possible it should use the framerate of the monitor that it's currently displayed on

In any case FF shouldn't fallback to SW VSYNC if Freesync / Gsync is used ( https://bugzilla.mozilla.org/show_bug.cgi?id=1160216#c5 ).

Comment 1

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

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Firefox Bug Husbandry Bot]

Resetting severity to default of --.

Comment 3

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is P3 (Backlog,) indicating it has been triaged, the bug's Severity is being updated to S3 (normal.)

Comment 4

[Robert Mader [:rmader]]

Changing dependencies: vsync gets enabled together with Webrender, so this is blocked by, not blocking WR - if I understood the issue correctly. As bug 1627057 indirectly blocks bug 1491303 this creates a loop, thus moving to "see also"