1689947 - Tab renders as a mostly gray screen (webrender on Mali-G31)

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Petru-Mugurel Lingurar [:petru]]

From github: https://github.com/mozilla-mobile/fenix/issues/17719.

Starting in version 84, each open page is displayed as a gray fill.
Navigation bar and preferences are displayed correctly.
The captured screenshot shows the correct image.

Device information:
Mecool Km1 AMLOGIC S905X3
Stock-ROM Android TV 10
Firefox 85.1.1, Firefox Beta 86.0.0-beta.1

Change performed by the Move to Bugzilla add-on.

Comment 1

[Petru-Mugurel Lingurar [:petru]]

This seems similar to https://bugzilla.mozilla.org/show_bug.cgi?id=1683936 which should have been fixed on 86.
Maybe something similar is needed for the " Mail-G31 MP2" that powers this also.

Comment 2

[Jamie Nicol [:jnicol]]

I don't think it's quite the same issue as that, as there is some stuff visible on the screen, it's just the wrong colours (and maybe missing quite a lot). But yeah, I think we need to disable webrender on Mali-G31 until we figure out the problem.

Comment 3

[Jamie Nicol [:jnicol]]

The main question for now is if any other GPUs are affected. There don't appear to be any others in the G3x series (only 31). And I assume the G5x ones are okay as they have at least an order of magnitude more users and no reports. So I think we're safe to just blocklist G31 for now.

Comment 4

[Jamie Nicol [:jnicol]]

Attachment: Bug 1689947 - Disable webrender on Mali-G31 devices. r?aosmond

A user reported completely broken rendering on their Mali-G31 device,
starting when webrender was enabled. Block webrender on Mali-G31
devices until the cause has been identified and fixed.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/11052b40320c
Disable webrender on Mali-G31 devices. r=aosmond

Comment 6

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/11052b40320c

Comment 7

[Jamie Nicol [:jnicol]]

Julien, we have another webrender bug on release unfortunately. It's very severe (unusable browser), but I think the number of Mali G31 users is fairly small (it seems to be designed for Android TV devices). So I would propose uplifting this to beta, and if there's going to be a point release then release too, but I'm not sure if it's worth driving one. Does that sound sensible?

Comment 8

[Jamie Nicol [:jnicol]]

I'm also going to look in to hooking up webrender on android to the downloadable blocklist, so that we hopefully don't get bitten by this again.

Comment 9

[Julien Cristau [:jcristau] (back August 18)]

Please request uplift to beta and release, we might have a new fenix release build coming up.

Comment 10

[Jamie Nicol [:jnicol]]

Comment on attachment 9200613 [details]
Bug 1689947 - Disable webrender on Mali-G31 devices. r?aosmond

Beta/Release Uplift Approval Request

• User impact if declined: Unusable browser for users with Mali-G31 GPUs (mostly Android TV devices)
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Falls back to opengl layers gfx backend which is still well tested and in widespread use.
• String changes made/needed:

Comment 11

[Pascal Chevrel:pascalc (PTO until Sept 2)]

Comment on attachment 9200613 [details]
Bug 1689947 - Disable webrender on Mali-G31 devices. r?aosmond

Approved for 86 beta 6, thanks.

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/3ac63cf9586b

Comment 13

[Julien Cristau [:jcristau] (back August 18)]

Comment on attachment 9200613 [details]
Bug 1689947 - Disable webrender on Mali-G31 devices. r?aosmond

approved for fenix 85.1.2

Comment 14

[Julien Cristau [:jcristau] (back August 18)]

https://hg.mozilla.org/releases/mozilla-release/rev/1177ff0696af

Comment 15

[Florin Strugariu [:Bebe]]

== Change summary for alert #28679 (as of Mon, 08 Feb 2021 19:06:49 GMT) ==

Improvements:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
6%	imdb	FirstVisualChange	linux64-shippable	nocondprof warm	554.67 -> 520.00
6%	imdb	SpeedIndex	linux64-shippable	nocondprof warm	555.07 -> 521.50
6%	imdb	ContentfulSpeedIndex	linux64-shippable	nocondprof warm	556.33 -> 524.08
5%	imdb	PerceptualSpeedIndex	linux64-shippable	nocondprof warm	560.94 -> 530.75

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=28679

Comment 16

[Julien Cristau [:jcristau] (back August 18)]

The change in this bug only affects android, comment 15 is likely unrelated.

Comment 17

[Florin Strugariu [:Bebe]]

The graph is really unstable in these alerts.
I will do more investigation

Comment 18

[Florin Strugariu [:Bebe]]

the alerts was triggered on beta by a multi commit patch and the regression is on one of the containing changes
https://treeherder.mozilla.org/jobs?repo=mozilla-beta&revision=3ac63cf9586bcc786acb6437a026ef26518b8c41&group_state=expanded&selectedTaskRun=A-89xhUUTPOqt6xrvwDsUw.0