Fenix: [Bug]Graphic corruption/glitch on pages

[PulkitGupta707]

Steps to reproduce: Appears randomly

Expected behavior: There shouldn't be any corruption/glitch. This is happening after yesterday's update.

Actual behavior: When i open a page there is some pixelated graphic corruption .

Device information Realme C3 running on android 10

• Android device: Android 10
• Fenix version: Firefox beta 79.1.0-beta.1

[PulkitGupta707]

They are on this page as well
Tried disabling dark reader but it didn't solve the problem

[jamienicol]

This looks very similar to this bug, and I can see that the Realme C3 has a Mali-G52 GPU, which would be affected.

@PulkitGupta707, can you check whether webrender is enabled by visiting about:support and reading what it says under "Compositing". It should say either "OpenGL" or "WebRender". If it says WebRender, did you manually enable webrender in about:config at any time?

[PulkitGupta707]

Yes, web render was enabled and disabling it fixed the issue. Also I don't think web render actually works on mediatek devices?
Edit: Yes i enabled it manually to see if it can improve page loading time but it didn't do anything and i forgot to disable it.

[jamienicol]

It's currently only enabled by default on some Adreno devices, other devices work to varying degrees. Some have issues like this, and some don't work at all. This bug should be fixed soon, at which point we may enable it by default on Mali devices such as yours. Please feel free to keep using it if you'd like, and file any more issues you see!

[estrogently]

After the latest update I'm getting similar but worse glitching on my Android 10 Mali-G77 MP11 device (screen recording).

Happening on both my regular install of stable (84.1.0-rc.1 (Build #2015780291); AC: 67.0.10, 899738987; GV: 84.0-20201207203640; AS: 67.0.01) as well as a fresh install of nightly (Nightly 201209 17:01 (Build #2015780427); AC: 70.0.20201209143130, c6d2a41d1; GV: 85.0a1-20201209034903; AS: 67.0.0), although it's a bit less severe on nightly.

Force-disabling the WebRender compositor through about:config solves the issue on nightly, but of course that's not really an option on stable.

[jamienicol]

Thanks for letting us know @estrogently. That looks like #16469, which should be fixed for the final 84.1.0 release and an upcoming nightly.

[estrogently]

Thanks for letting us know @estrogently. That looks like #16469, which should be fixed for the final 84.1.0 release and an upcoming nightly.

Thanks! Glad it's known and will (hopefully) be fixed in the final release.
(Not entirely sure why the RC was pushed out as an update for the normal/stable app with WebRender enabled for devices where it was known to be broken then, though)

[jamienicol]

It wasn't known to be broken at the time. The issue is due to a driver bug on Mali-G77.