1765218 - Desktop visible through page

Status: RESOLVED DUPLICATE of bug 1815481

(Core :: Graphics, defect)

Description

[Tyson Smith [:tsmith]]

Attachment: testcase.html

Sections of the page suddenly become transparent and the desktop is visible. I've seen this happen many times in the past but was unable to consistently reproduce the issue.

While reducing a test case for a separate issue I got a test case that will reproduce this behavior.

I am running Ubuntu 20.04.

STR:

• Open the test case
• If the problem is not apparent open the hamburger menu and move mouse up and down over the options.

Comment 1

[Tyson Smith [:tsmith]]

Attachment: screenshot.jpg

Comment 2

[Jim Mathies [:jimm]]

I seem to remember a similar issue when we were shipping webrender. Andrew, any thoughts?

Comment 3

[Brad Werth [:bradwerth]]

Possibly related to Bug 1669840.

Comment 4

[Robert Mader [:rmader]]

Hi Tyson. Could you attach the content of your about:support (Copy text to clipboard) here so we know what kind of setup you're running? There's a high chance that this is somewhat GPU driver related.

Comment 5

[Tyson Smith [:tsmith]]

Attachment: about_support.txt

With the latest build I don't see the same missing chunk but I do see icons flicking through.

Adding setTimeout(() => { window.location.reload(true) }, 100) to the test case makes it easier to see when it happens.

Comment 6

[Robert Mader [:rmader]]

(In reply to Tyson Smith [:tsmith] from comment #5)

Created attachment 9274733 [details]
about_support.txt

Thanks a lot! So IIUC this is in a virtual machine, running an X11 session - is that correct? If you have time, could you check if:

1. running a Wayland session (i.e. Firefox runs on Xwayland) helps?
2. running Firefox with MOZ_ENABLE_WAYLAND=1 in a Wayland session helps?
3. setting gfx.x11-egl.force-disabled in about:support (in the current X11 setup) helps?

Also, could you add what kind of host machine this is on, especially GPU and driver (Nvidia?).

Comment 7

[Tyson Smith [:tsmith]]

(In reply to Robert Mader [:rmader] from comment #6)

Thanks a lot! So IIUC this is in a virtual machine, running an X11 session - is that correct?

Yes

1. running a Wayland session (i.e. Firefox runs on Xwayland) helps?

No

2. running Firefox with MOZ_ENABLE_WAYLAND=1 in a Wayland session helps?

Black box flickers (instead of transparent box).

3. setting gfx.x11-egl.force-disabled in about:support (in the current X11 setup) helps?

No

Also, could you add what kind of host machine this is on, especially GPU and driver (Nvidia?).

Windows 10 (21H2), Nvidia GTX1080

This also seems to go away with gfx.webrender.software=true.

Comment 8

[Robert Mader [:rmader]]

(In reply to Tyson Smith [:tsmith] from comment #7)

...

Thanks!

Windows 10 (21H2), Nvidia GTX1080

Oof, ok, many layers where things can go wrong here.

This also seems to go away with gfx.webrender.software=true.

Yeah, that's likely the solution we need to take here (disabling hardware acceleration).

Comment 9

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

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

For more information, please visit auto_nag documentation.

Comment 10

[Andrew Osmond [:aosmond] (he/him)]

With HW-WR, does flipping gfx.webrender.allow-partial-present-buffer-age to false and/or gfx.webrender.max-partial-present-rects to 0 help? Just wondering if this is partial present related. Probably best to disable HW-WR when in a VM.

Comment 11

[Tyson Smith [:tsmith]]

(In reply to Andrew Osmond [:aosmond] (he/him) from comment #10)

gfx.webrender.allow-partial-present-buffer-age to false

Still reproduces

gfx.webrender.max-partial-present-rects to 0

Still reproduces

gfx.webrender.allow-partial-present-buffer-age to false and gfx.webrender.max-partial-present-rects to 0

Still reproduces

Comment 12

[Andrew Osmond [:aosmond] (he/him)]

A bug should be filed against the upstream mesa for this. The vmwgfx / svga driver is open source.