1853573 - border-image, background-repeat, border-style dotted/dashed no longer render [Adreno 3xx]

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Kestrel]

Attachment: Comparison of border-image rendering before (top) and after

Samsung Galaxy Tab 4 (SM-T530)
LineageOS 18.1 (Android 11)
Qualcomm Adreno (TM) 305
OpenGL ES 3.0 V@140.0

https://codepen.io/jsnkuhn/pen/PoRPKOz?editors=1100

border-image is mostly missing, some parts may appear briefly when zooming. border-image-repeat: space is more likely to render. Any images within the affected element may also fail to render.

border-style dotted/dashed and background-repeat are similarly affected.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=7313b6429e48b58bd38ab3be47999be475f2ba6b&tochange=8c932e681e021cc4d2f8c9f72e20ce5941eb689e

Regressed by Bug 1778032.

Comment 1

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

:nical, since you are the author of the regressor, bug 1778032, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Jamie Nicol [:jnicol]]

I can repro on a Moto G Play (Adreno 306). Not on other 3xx devices, so seems specific to 305 and 306, and perhaps certain driver versions

Comment 3

[Jamie Nicol [:jnicol]]

The presence of these two if statements in the shader appears to cause the bug, even if that flag isn't actually used.

Removing either of the if statements fixes it, though is obviously incorrect.

Luckily replacing the if statements with a mix() appears to fix it

Comment 4

[Jamie Nicol [:jnicol]]

Attachment: Bug 1853573 - Implement vec2_scalar fract() in swgl. r?#gfx-reviewers

Comment 5

[Jamie Nicol [:jnicol]]

Attachment: Bug 1853573 - Avoid shader miscompile on Adreno 3xx. r?#gfx-reviewers

The repeated if-statements in the existing shader code appear to be
miscompiled on certain Adreno 3xx devices. Replacing them with a mix()
statement appears to avoid the bug.

Depends on D188818

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ad90c7167010
Implement vec2_scalar fract() in swgl. r=gfx-reviewers,lsalzman
https://hg.mozilla.org/integration/autoland/rev/f8ff55014631
Avoid shader miscompile on Adreno 3xx. r=gfx-reviewers,lsalzman

Comment 7

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/ad90c7167010
https://hg.mozilla.org/mozilla-central/rev/f8ff55014631

Comment 8

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

The patch landed in nightly and beta is affected.
:jnicol, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox118 to wontfix.

For more information, please visit BugBot documentation.

Comment 9

[Jamie Nicol [:jnicol]]

I think given this affects a low number of users, and shader changes are never fully without risk, it's probably best not to uplift to release at the very last minute!

Comment 10

[Kestrel]

Confirmed fixed on latest Nightly 119.0a1 (GV 20230924092410).