1721795 - Buttons drawn with a diagonal artifact, rounded corners are missing [Adreno 3xx]

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Stefan [:stefanh]]

Spun off from bug 1720841:

See https://bugzilla.mozilla.org/attachment.cgi?id=9231507 (see also testcase in url field). I see this in the latest nightly (92) and beta (91) with:
Samsung Galaxy S4 (GT-I9506)
Android 5.0.1
Qualcomm Adreno (TM) 330
OpenGL ES 3.0 V@84.0

Disabling webrender makes buttons look normal.

I assume it happens in 90 as well but it's unusable because of bug 1720841.

Comment 1

[Dzmitry Malyshau [:kvark]]

Thank you for reporting! Pinging :jnicol on Matrix.

Comment 2

[Jamie Nicol [:jnicol]]

This looks like another case of bug 1630356, this time due to vMixColors in cs_border_solid.glsl. Packing it in a vec2 works around the bug.

Comment 3

[Jamie Nicol [:jnicol]]

Attachment: Bug 1721795 - Pack cs_border_solid's vMixColors in to vector to work around driver bug. r?#gfx-reviewers

We have in the past encountered a driver bug on Adreno 3xx devices
where using a flat scalar varying causes the fragment shader output to
be incorrect. See bugs 1630356 and 1705433.

We have now encountered this in cs_border_solid too, due to
vMixColors. As before, packing the varying in to a vector works around
the bug.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d071aa321f67
Pack cs_border_solid's vMixColors in to vector to work around driver bug. r=gfx-reviewers,lsalzman

Comment 5

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/d071aa321f67

Comment 6

[Stefan [:stefanh]]

With my Samsung Galaxy S4 GT-I9506 (Android 5.0.1, Qualcomm Adreno 330) I can verify that buttons now are drawn correct with the 20210730093652 build.

Comment 7

[Jamie Nicol [:jnicol]]

Comment on attachment 9233742 [details]
Bug 1721795 - Pack cs_border_solid's vMixColors in to vector to work around driver bug. r?#gfx-reviewers

Beta/Release Uplift Approval Request

• User impact if declined: Border elements rendered incorrectly for users with Adreno 3xx GPUs
• Is this code covered by automated tests?: Yes
• 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): Minor change to shader code to work around driver bug. The same workaround has previously been applied to several other shaders without any issues, so should be safe for this shader too.
• String changes made/needed:

Comment 8

[Julien Cristau [:jcristau]]

Comment on attachment 9233742 [details]
Bug 1721795 - Pack cs_border_solid's vMixColors in to vector to work around driver bug. r?#gfx-reviewers

approved for geckoview/fenix 91

Comment 9

[Julien Cristau [:jcristau]]

https://hg.mozilla.org/releases/mozilla-beta/rev/7ff8e06769e0