Glitchy behaviour in Firefox 88.0

I just did a -current upgrade from last 2 weeks and have inherited a number of strange glitches. (See attached screenshot).

They're most noticable in Firefox in particular places on particular sites, and particularly when highlighting text.

I am on Intel graphics, however the driver has not changed in this period it seems, nor has my X11 config. I use xfce for my desktop.

Any tips welcome :-)

Andypoo.

Update: I could have sworn I noticed odd behaviour also in sddm and on some window decorations in other places, but maybe it is unrelated.

I can't help I'm afraid but I had these triangular glitches with Blender -- both SBo builds. AMD graphics here.

I downgraded Firefox from mozilla-firefox-88.0-x86_64-1 to mozilla-firefox-87.0-x86_64-2 and the issues in the previous screenshot went away.

I just did another -current upgrade, this time to Firefox 88.0.1 and wanted to report that the issue is still present.

Downgrading to mozilla-firefox-87.0-x86_64-2 resolved the issue again.

If anybody has any tips on something to look for, please let me know.

Well, I just can say I've got the same here...

Wild guess here, but maybe WebRender was enabled?

I've seen at least one report that they planned to enable it in Firefox 88 for some Linux platforms: https://www.reddit.com/r/linux/comme...ed_by_default/ but I'm not sure if that happened.

Check about:config - look for the gfx.webrender.all setting. If it's true, toggle it back to false and see if that fixes things.

Added: Looks like WebRender was enabled for some combinations - https://bugzilla.mozilla.org/show_bug.cgi?id=1696495

Does not seem to be the case.

gfx.webrender.all is false (default). All of my gfx.webrender config entries are unchanged/default.

I upgraded to 88.0.1 again to make sure the default hadn't changed, and it is still false there also.

Maybe check about:support to see if anything has changed? (There's too much info there, but you can copy the text-only versions from 87 & 88.x and diff to see if anything jumps out.)

Ooo, thanks for that. That was a great tip and revealed this gem. So you were definitely on the right track there.

Features
-Compositing: Basic
+Compositing: WebRender

So compositor has changed somehow between 87 and 88. And this is likely where the issues are coming from.
Now to work out what that means :-) Or as a worst-case, how to disable it.. gfx.webrender.all is still false.

From reading these issues,
https://bugzilla.mozilla.org/show_bug.cgi?id=1694792
https://bugzilla.mozilla.org/show_bug.cgi?id=1691691

It seems that the underlying issue with webrender on some Intel graphics chipsets is not new, however something has changed in 88 to use webrender in more contexts it seems.
Is this possibly something that was changed at the compile time on Slackware's side during the switch to 88.0?

Andrew.

I don't know if this is any help or not, but on 14.2, I just downloaded and am using 88.0.1 and don't see anything wrong anywhere. Could that mean that it's something in Slackware current that's not right and not in Firefox itself? I don't use Firefox anymore since they jumped on the bandwagon of trying to tell me I'm too white, so this was just a quick check to see if it was 'glitchy' on other versions of Slackware in the hopes that it may be of some use in helping. After this post using it (Firefox) it's getting uninstalled again, heh.

As a workaround for myself (and others on affected Intel chipsets), setting gfx.webrender.force-disabled to true and restarting returns to the Basic renderer.

I'm not sure if this is the most ideal workaround, but if there is an issue there that can't be fixed and isn't caused by a Slackware compile option, then I guess it is something I can live with :-)
It only returns me to where I was on 87.0, so that is bearable.

Andrew.

Originally Posted by Andypoo As a workaround for myself (and others on affected Intel chipsets)

You might also try without using the intel driver to get gfx to work

removepkg /var/log/packages/xf86-video-intel-*

and then restart X/logout-login.

Originally Posted by Andypoo As a workaround for myself (and others on affected Intel chipsets), setting gfx.webrender.force-disabled to true and restarting returns to the Basic renderer. I'm not sure if this is the most ideal workaround, but if there is an issue there that can't be fixed and isn't caused by a Slackware compile option, then I guess it is something I can live with :-) It only returns me to where I was on 87.0, so that is bearable. Andrew.

A big "thank you" to you, it works nicely now.

Just an update, this issue no longer seems present in Firefox 89.0 (and 89.0.2) so the workaround is no longer necessary and can/should likely be removed.

Enjoy!
Andrew.