1655344 - Basic layers on Ubuntu 18.04: Firefox jams image on the screen (kernel 5.4; virtual machine; fixed by setting "IOMMU=pt" in grub)

Status: RESOLVED WORKSFORME

(Core :: Graphics: Layers, defect, P3)

Description

[luca.dgh]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0

Steps to reproduce:

The problem appears just opening Firefox, as well when I access sites as Amazon Prime Video or Youtube, but generally everywhere, even opening this site to write this bug report.
My system is Ubuntu 18.04, Ryzen 3 3200 G with Radeon Vega 8 integrated GPU, 8 GB RAM.

Actual results:

The image appears dazzled and confused, sometimes more some time less (just some lines on the screen, I made a short video to understand better https://drive.google.com/file/d/1KySFg3ZnwqJIP6WhMRK2s1Yg6Vym52l2/view?usp=sharing

Expected results:

The image should have been clean, I can say that on my system I have Chromium installed as well (actually I don't like it) and this problem does not appear on that browser.

Comment 1

[BugBot [:suhaib / :marco]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Darkspirit]

Thanks for the report! Please open about:support, click on "Copy text to clipboard" and paste it here.

Comment 3

[luca.dgh]

Attachment: about:support

Comment 4

[Darkspirit]

Can you open about:crashes, submit unsent crash reports (if there are any) and copy their IDs (bp-xxxxxxxxxxx) to Bugzilla? Thanks

Comment 5

[luca.dgh]

(In reply to Jan Andre Ikenmeyer [:darkspirit] from comment #4)

Can you open about:crashes, submit unsent crash reports (if there are any) and copy their IDs (bp-xxxxxxxxxxx) to Bugzilla? Thanks

no crashes reported in about:crashes

Comment 6

[luca.dgh]

I downloaded 79 beta 9 from Mozilla site, the problem persists.

Comment 7

[luca.dgh]

firefox 80.0a1 nightly looks to be not affected from the problem. There is a way to install it system wide?

Comment 8

[Darkspirit]

(In reply to luca.dgh from comment #7)

firefox 80.0a1 nightly looks to be not affected from the problem.

I think it's because - on Linux - only Nightly uses OpenGL rendering by default.
If you open about:config in Nightly, set gfx.webrender.force-disabled to true and restart Nightly, can you reproduce the problem there, too?

There is a way to install it system wide?

Unfortunately would have to create your own ~/.local/share/applications/Nightly.desktop file if you want to use Nightly with more comfort.
The other option is enabling WebRender (OpenGL rendering) on Stable: Open about:config, set gfx.webrender.all to true and restart Firefox.

Comment 9

[luca.dgh]

(In reply to Jan Andre Ikenmeyer [:darkspirit] from comment #8)

(In reply to luca.dgh from comment #7)

firefox 80.0a1 nightly looks to be not affected from the problem.

I think it's because - on Linux - only Nightly uses OpenGL rendering by default.
If you open about:config in Nightly, set gfx.webrender.force-disabled to true and restart Nightly, can you reproduce the problem there, too?

You are right, disabling OpenGL Nightly has the same problem, but only 10% compared to 78.0.2

There is a way to install it system wide?

Unfortunately would have to create your own ~/.local/share/applications/Nightly.desktop file if you want to use Nightly with more comfort.
The other option is enabling WebRender (OpenGL rendering) on Stable: Open about:config, set gfx.webrender.all to true and restart Firefox.
You are right too, now I have a good experience with Firefox.

So I understand that Firefox is replacing OpenGL with xfwm4, well if is that, I can say that this is the second bad experience with that renderer: Mate has broken his 20.04 live CD installer (for certain graphic cards) because they used xfwm4.
I think that is not the right time to abandon OpenGL.

Comment 10

[luca.dgh]

(In reply to Jan Andre Ikenmeyer [:darkspirit] from comment #8)

(In reply to luca.dgh from comment #7)

    firefox 80.0a1 nightly looks to be not affected from the problem.

I think it's because - on Linux - only Nightly uses OpenGL rendering by default.
If you open about:config in Nightly, set gfx.webrender.force-disabled to true and restart Nightly, can you reproduce the problem there, too?

You are right, disabling OpenGL Nightly has the same problem, but only 10% compared to 78.0.2

    There is a way to install it system wide?

Unfortunately would have to create your own ~/.local/share/applications/Nightly.desktop file if you want to use Nightly with more comfort.
The other option is enabling WebRender (OpenGL rendering) on Stable: Open about:config, set gfx.webrender.all to true and restart Firefox.

You are right too, now I have a good experience with Firefox.

So I understand that Firefox is replacing OpenGL with xfwm4, well if is that, I can say that this is the second bad experience with that renderer: Mate has broken his 20.04 live CD installer (for certain graphic cards) because they used xfwm4.
I think that is not the right time to abandon OpenGL.

Comment 11

[Darkspirit]

I think that is not the right time to abandon OpenGL.

It's going the other direction: On Linux, Firefox Stable and Beta still use CPU software rendering by default while Nightly already defaults to GPU OpenGL rendering if Mesa drivers are used. With gfx.webrender.all, one can manually enable OpenGL rendering, even on Stable. As of bug 1653612 WebRender will be enabled by default in the next Early Beta. Some releases later it will be enabled by default in Stable.

Was this bug introduced by Firefox 78? If yes, could you try to find a regression range?
$ sudo apt-get install python3-pip
$ pip3 install --upgrade mozregression
$ ~/.local/bin/mozregression --good 77 --bad 78 --pref gfx.webrender.force-disabled:true

Comment 12

[luca.dgh]

Some good news.
I was trying to solve the problem and a friend of mine said me to check the Bios and switch on the option "3D Mark01 Enhancement".
Now I have a better experience with Firefox 78.0.2 , 99% perfect (very rare problems with image on the screen, sometimes streaming can fails because the internet not the browser).
I tried to change gfx.webrender.all to false, but the problem was back.
So in this moment I feel much better with Firefox.

To answer your question "Was this bug introduced by Firefox 78?"
I can't say exactly yes or no because the 78.0.2 has been installed on 16th of July (dpkg log says that) and after that I didn't use this machine for a while. But I'm sure that before that date I've never had any problem at all.

Comment 13

[BugBot [:suhaib / :marco]]

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

For more information, please visit auto_nag documentation.

Comment 14

[luca.dgh]

Hi to all.
After surfing internet for a long time I found a solution.
It looks like that new kernel 5.4 has not a good feeling with Radeon Vega GPU, specially if on the machine is installed a virtual machine that requires IOMMU enabled.
I'm not a specialist in kernel stuff, but I tried different workaround and finally I found the magic touch that fixed my problem: in grub I need a launch option "IOMMU=pt".
Now Firefox works like a charm.
Sorry for bothering.

Comment 15

[Cristian Fogel [:cfogel]]

@ ktaeleman, considering the previous comment; is there something that can be done on the Firefox side of things or can we close this report?

Comment 16

[Kris Taeleman (:ktaeleman)]

@Andrew: You know a whole lot more than I do here. Is there anything we should do on our side for this?