Bug#1101967: firefox: webrender acceleration creates UI and rendering bugs in latest update

[tv.debian]

Package: firefox
Version: 137.0-1
Severity: normal

Dear beloved and much esteemed Maintainer,


forcing webrender material acceleration used to work fine on my AMD
hardware, but since latest update it creates large transparent blocks in
webpages on scrolling, disables some elements ( like drop-down menus on
https://www.debian.org/distrib/packages ), and renders UI element broken
or very unresponsive (like the main pancakes menu).
Disabling webrender material acceleration fixes the problems. So while
the forced acceleration is not standard, it looks like a regression in
that area from previous versions.

I am running a Wayland session in Plasma KDE, the GPU is an AMD Radeon
7900XT.

Thank you for your attention.

-- System Information:
Debian Release: trixie/sid
APT prefers testing
APT policy: (990, 'testing'), (500, 'unstable'), (101, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.14.0-deb64 (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_CPU_OUT_OF_SPEC, TAINT_UNSIGNED_MODULE
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8),
LANGUAGE=fr:en_US
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages firefox depends on:
ii debianutils 5.21
ii fontconfig 2.15.0-2.2
ii libasound2t64 1.2.13-1+b1
ii libatk1.0-0t64 2.56.1-2
ii libc6 2.41-6
ii libcairo-gobject2 1.18.4-1+b1
ii libcairo2 1.18.4-1+b1
ii libdbus-1-3 1.16.2-2
ii libevent-2.1-7t64 2.1.12-stable-10+b1
ii libffi8 3.4.7-1
ii libfontconfig1 2.15.0-2.2
ii libfreetype6 2.13.3+dfsg-1
ii libgcc-s1 14.2.0-19
ii libgdk-pixbuf-2.0-0 2.42.12+dfsg-2
ii libglib2.0-0t64 2.84.0-2
ii libgtk-3-0t64 3.24.49-3
ii libnspr4 2:4.36-1
ii libnss3 2:3.110-1
ii libpango-1.0-0 1.56.3-1
ii libstdc++6 14.2.0-19
ii libvpx9 1.15.0-2
ii libx11-6 2:1.8.12-1
ii libx11-xcb1 2:1.8.12-1
ii libxcb-shm0 1.17.0-2+b1
ii libxcb1 1.17.0-2+b1
ii libxcomposite1 1:0.4.6-1
ii libxdamage1 1:1.1.6-1+b2
ii libxext6 2:1.3.4-1+b3
ii libxfixes3 1:6.0.0-2+b4
ii libxrandr2 2:1.5.4-1+b3
ii procps 2:4.0.4-7
ii zlib1g 1:1.3.dfsg+really1.3.1-1+b1

Versions of packages firefox recommends:
ii libavcodec-extra61 [libavcodec61] 7:7.1.1-1+b1

Versions of packages firefox suggests:
ii fonts-lmodern 2.005-1
ii fonts-stix [otf-stix] 1.1.1-5
ii libcanberra0 0.30-17+b1
ii libgssapi-krb5-2 1.21.3-5
pn pulseaudio <none>

-- no debconf information

[Geoff]

Package: firefox
Version: 137.0-1
Followup-For: Bug #1101967
X-Debbugs-Cc: ***@bigpond.com

Hi, I have the exact problem described. How do you disable "webrender material acceleration" actually?

I've tried turning off "Use hardware acceleration when available" under advanced preferences and also set gfx.webrender.software to true and restarted the browser but still have the issue.

Thanks.

-- System Information:
Debian Release: trixie/sid
APT prefers unstable
APT policy: (700, 'unstable'), (650, 'testing'), (600, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.13-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages firefox depends on:
ii debianutils 5.21
ii fontconfig 2.15.0-2.2
ii libasound2t64 1.2.13-1+b1
ii libatk1.0-0t64 2.56.1-2
ii libc6 2.41-6
ii libcairo-gobject2 1.18.4-1+b1
ii libcairo2 1.18.4-1+b1
ii libdbus-1-3 1.16.2-2
ii libevent-2.1-7t64 2.1.12-stable-10+b1
ii libffi8 3.4.7-1
ii libfontconfig1 2.15.0-2.2
ii libfreetype6 2.13.3+dfsg-1
ii libgcc-s1 14.2.0-19
ii libgdk-pixbuf-2.0-0 2.42.12+dfsg-2
ii libglib2.0-0t64 2.84.1-1
ii libgtk-3-0t64 3.24.49-3
ii libnspr4 2:4.36-1
ii libnss3 2:3.110-1
ii libpango-1.0-0 1.56.3-1
ii libstdc++6 14.2.0-19
ii libvpx9 1.15.0-2
ii libx11-6 2:1.8.12-1
ii libx11-xcb1 2:1.8.12-1
ii libxcb-shm0 1.17.0-2+b1
ii libxcb1 1.17.0-2+b1
ii libxcomposite1 1:0.4.6-1
ii libxdamage1 1:1.1.6-1+b2
ii libxext6 2:1.3.4-1+b3
ii libxfixes3 1:6.0.0-2+b4
ii libxrandr2 2:1.5.4-1+b3
ii procps 2:4.0.4-7
ii zlib1g 1:1.3.dfsg+really1.3.1-1+b1

Versions of packages firefox recommends:
ii libavcodec61 7:7.1.1-1+b1

Versions of packages firefox suggests:
ii fonts-lmodern 2.005-1
pn fonts-stix | otf-stix <none>
ii libcanberra0 0.30-17+b1
ii libgssapi-krb5-2 1.21.3-5
pn pulseaudio <none>

-- no debconf information

[tv.debian]

Post by tv.debian
Package: firefox
Version: 137.0-1
Followup-For: Bug #1101967
Hi, I have the exact problem described. How do you disable "webrender material acceleration" actually?
I've tried turning off "Use hardware acceleration when available" under advanced preferences and also set gfx.webrender.software to true and restarted the browser but still have the issue.
Thanks.
Debian Release: trixie/sid
APT prefers unstable
APT policy: (700, 'unstable'), (650, 'testing'), (600, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 6.13-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
ii debianutils 5.21
ii fontconfig 2.15.0-2.2
ii libasound2t64 1.2.13-1+b1
ii libatk1.0-0t64 2.56.1-2
ii libc6 2.41-6
ii libcairo-gobject2 1.18.4-1+b1
ii libcairo2 1.18.4-1+b1
ii libdbus-1-3 1.16.2-2
ii libevent-2.1-7t64 2.1.12-stable-10+b1
ii libffi8 3.4.7-1
ii libfontconfig1 2.15.0-2.2
ii libfreetype6 2.13.3+dfsg-1
ii libgcc-s1 14.2.0-19
ii libgdk-pixbuf-2.0-0 2.42.12+dfsg-2
ii libglib2.0-0t64 2.84.1-1
ii libgtk-3-0t64 3.24.49-3
ii libnspr4 2:4.36-1
ii libnss3 2:3.110-1
ii libpango-1.0-0 1.56.3-1
ii libstdc++6 14.2.0-19
ii libvpx9 1.15.0-2
ii libx11-6 2:1.8.12-1
ii libx11-xcb1 2:1.8.12-1
ii libxcb-shm0 1.17.0-2+b1
ii libxcb1 1.17.0-2+b1
ii libxcomposite1 1:0.4.6-1
ii libxdamage1 1:1.1.6-1+b2
ii libxext6 2:1.3.4-1+b3
ii libxfixes3 1:6.0.0-2+b4
ii libxrandr2 2:1.5.4-1+b3
ii procps 2:4.0.4-7
ii zlib1g 1:1.3.dfsg+really1.3.1-1+b1
ii libavcodec61 7:7.1.1-1+b1

Hello, there are several settings involved, the "use recommended
performance settings" and "use hardware acceleration when available"
from the general settings page are a start. On Linux most of hardware
acceleration is blacklisted anyway, so those settings won't do much.

If you want more fine-grained options you need to open the
"about:config" advanced settings page, then filter for "webrender".

"gfx.webrender.all" and "gfx.webrender.compositor" will turn hardware
acceleration IF your hardware and software (mesa) are not blacklisted.
If you want to enable hardware acceleration anyway, to test it at your
own risk, then flip "gfx.webrender.compositor.force-enabled" to true,
and "gfx.webrender.software" to false.

Conversely if you want to force software rendering turn everything to
false, and "gfx.webrender.software" to true.

You need to restart Firefox after making any change.

I am only talking about webrender here, not to be confused with webgl
acceleration which can be enabled only on Firefox development version
AFAIK, and is very unstable.

Hope it helps.

[Geoff]

Package: firefox
Version: 137.0.1-1
Followup-For: Bug #1101967
X-Debbugs-Cc: ***@bigpond.com

I can confirm that gfx.webrender.compositor.force-enabled was the offending option and was set to true. This as well as the other mentioned options are now default.

I don't remember changing it but it must have worked ok in previous versions.

Thanks!

[tv.debian]

Post by tv.debian
Package: firefox
Version: 137.0.1-1
Followup-For: Bug #1101967
I can confirm that gfx.webrender.compositor.force-enabled was the offending option and was set to true. This as well as the other mentioned options are now default.
I don't remember changing it but it must have worked ok in previous versions.
Thanks!

I tested an upstream version of Firefox 137 and there the default is to
disable hardware acceleration for webrender on Linux with my hardware.
Despite the general "use default performance settings" being ticked, or
even when ticking manually "use hardware acceleration when available"
the result doesn't change, no hw acceleration is enforced, and the
described bugs don't manifest.
When manually enabling through the "about:config" page the result is the
same, the bugs appear. So the regression is either in upstream Firefox,
or in some other library shipped in Debian Unstable (Mesa comes to mind).
I humbly admit that I am not familiar with Firefox development and can't
make a guess as to what broke. Firefox change-log doesn't strike me as
obviously suspicious in that area.