1887315 - [driver bug] webrender blitting into backbuffer broken on adreno a3xx using Freedreno

Status: UNCONFIRMED

(Core :: Graphics: WebRender, defect)

Description

[Michael.Srba]

Attachment: attachment.tar.xz

Steps to reproduce:

Open any website (even empty new tab) on an msm8916 device using Mesa driver stack (e.g https://wiki.postmarketos.org/wiki/Samsung_Galaxy_A3_2015_(samsung-a3))

OS: Linux (postmarketOS)

This is a problem with Firefox on my phone or tablet
kind of, but it's the Linux version of Firefox

Actual results:

some tiles don't get blitted properly into the backbuffer (see attachments)
FD_MESA_DEBUG=flush works around the issue, but causes considerable slowdown

There are some workarounds for the proprietary driver mentioning similar issues, but pretending to be the proprietary driver in order for them to be applied doesn't fix the issue.

Unlike with the proprietary driver, it should be possible to fix the bug in the driver itself, unfortunately a3xx isn't actively maintained in Mesa (though they would presumably accept a patch)

also, text rendering is broken (even with FD_MESA_DEBUG=flush), but that's probably a separate issue

Expected results:

the site renders properly on a3xx using Mesa

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Graphics: WebRender' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

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

The severity field is not set for this bug.
:gw, could you have a look please?

For more information, please visit BugBot documentation.