User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

1. Open any long page, for example:
   https://src.fedoraproject.org/rpms/vim/blob/rawhide/f/vim.spec
2. Page is rendered correctly just after load
3. Start scrolling down with wheel of the mouse or browser slider.

Actual results:

In about half of the page its content starts to corrupt as shown on the attached screenshot.

Expected results:

Page content should not corrupt.

Linux Fedora 35 with 5.15.16-200.fc35.x86_64
Mesa: 21.3.4
GNOME 41.3 Wayland
GPU: 01:05.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] RS880 [Radeon HD 4200] [1002:9710], iGPU on M4A785TD-V EVO mainboard

Modified settings in about:config:
gfx.webrender.enabled true
layers.acceleration.force-enabled true
media.ffmpeg.vaapi.enabled true
widget.wayland-dmabuf-vaapi.enabled true

The Bugbug bot thinks this bug should belong to the 'Core::Layout: Scrolling and Overflow' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

If you remove gfx.webrender.enabled=true, does it work? I don't see this on Windows not on my Fedora workstation on Nightly. But ISTR similar bugs in the past with text clipping in WebRender.

Thanks for the report!
You can remove

• gfx.webrender.enabled
• layers.acceleration.force-enabled
• widget.wayland-dmabuf-vaapi.enabled

from about:config as they won't have any effect anymore.

Does this bug still occur after setting layers.async-pan-zoom.enabled to false and restarting Firefox? (bug 1726431)

When I set gfx.webrender.enabled to false then issue does not occur. But in such situation I lost hardware acceleration which i.e. results in CPU load increase during video playing from ~60% to ~240% which is significant.
Disabling layers.acceleration.force-enabled and widget.wayland-dmabuf-vaapi.enabled seems to change nothing in my case.

Setting layers.async-pan-zoom.enabled to false does not help and issue still occurs after browser restart.

(In reply to mac from comment #6)

Setting layers.async-pan-zoom.enabled to false does not help and issue still occurs after browser restart.

Thanks! Then it's still the original hardware/driver bug:

[1002:9710], iGPU

Because of text glitches, bug 1673939 blocked 0x9710 from getting hardware WebRender.

The hardware/driver bug would need to be fixed in Mesa: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3720

(In reply to Darkspirit from comment #7)

(In reply to mac from comment #6)

Setting layers.async-pan-zoom.enabled to false does not help and issue still occurs after browser restart.

Thanks! Then it's still the original hardware/driver bug:

(Please set layers.async-pan-zoom.enabled back to true.)