1637497 - Partial present causes glitches on Win7 with non-Aero theme

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect, P2)

Description

[Asif Youssuff]

Reported: https://www.reddit.com/r/firefox/comments/ghkj22/terrible_graphical_glitches_on_nightly/

Since a few days ago, I've been having a lot of tearing-like glitches on Firefox Nightly. They happen almost every time I:
Alt-Tab into Firefox (or switch to a Nightly window using the taskbar, or minimize it by clicking on a maximized browser window)
Switch between two Firefox windows
Close a file selection or other explorer dialog (less often)

It does not happen when switch to a different tab, in fact that is - along with moving the mouse in the general area where the bug is happening - a way to make the "ghost" image disappear. Usually it's the bottom half of the screen that doesn't "refresh".

Disabling WR resolves the issue.

Comment 1

[Asif Youssuff]

Attachment: about:support

Comment 2

[Jessie [:jbonisteel] pls NI]

Looks like some screen tearing happening for some folks on Win7

Comment 3

[Jessie [:jbonisteel] pls NI]

Hey Sotaro - can you reproduce this?

Comment 4

[Jessie [:jbonisteel] pls NI]

NI-ing Rares to see if you can repro

Comment 5

[Rares Doghi, Desktop QA]

Hi, I was able to reproduce this issue In our latest Nightly build, Beta as well as Release after setting the gfx.webrender.all = true, ill attach a few screenshots and a screencapture to this issue.

I will also attach the about:support from my computer, it happens on my Nvidia GT 730 as well.

Comment 6

[Jessie [:jbonisteel] pls NI]

Sotaro, can you see if you can repro?

Comment 7

[Rares Doghi, Desktop QA]

Attachment: 2020-05-15_17h19_11.mp4

Comment 8

[Rares Doghi, Desktop QA]

Attachment: tearrRlease.png

Comment 9

[Rares Doghi, Desktop QA]

Attachment: aboutSupport730.txt

Comment 10

[Rares Doghi, Desktop QA]

Attachment: aboutSupport730WebrenderON.txt

attached the aboutSupport file with Webrender enabled.

Comment 11

[Darkspirit]

I can reproduce this window expose problem only when Win7 Aero theme is disabled.
This problem looks a bit like what I saw on KDE a year ago: bug 1518796. (bug 1502519 looks different, but is still reproducible for me on KDE.)
i3 also suffers from a window expose bug: bug 1572625

Comment 13

[Jeff Muizelaar [:jrmuizel]]

As a band aid we can probably disable WebRender when we don't have DWM: gfxWindowsPlatform::GetPlatform()->DwmCompositionEnabled()
Andrew, want to make a patch for that?

Comment 14

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

(In reply to Jeff Muizelaar [:jrmuizel] from comment #13)

As a band aid we can probably disable WebRender when we don't have DWM: gfxWindowsPlatform::GetPlatform()->DwmCompositionEnabled()
Andrew, want to make a patch for that?

Sure. I'll fork the bug so we can track the original issue.

Comment 15

[Sotaro Ikeda [:sotaro]]

(In reply to Jessie [:jbonisteel] pls NI from comment #6)

Sotaro, can you see if you can repro?

By disabling DWM manually, I confirmed that the problem happened. It seems that :aosmond is already working for the bug.

Comment 16

[Darkspirit]

Confirmed: comment 7 and bug 1638431 are caused by partial present.

https://hg.mozilla.org/integration/autoland/shortlog/5674dddc94f8
last good: mozregression --repo autoland --launch 8f47bf276c0e499246652701cd6b9b23e090a0d8 --pref gfx.webrender.all:true -a https://reddit.com -a https://mozilla.org
first bad: mozregression --repo autoland --launch 5674dddc94f8a8e9c034c80b3650417bf39ba697 --pref gfx.webrender.all:true -a https://reddit.com -a https://mozilla.org

First bad is fine if you set gfx.webrender.max-partial-present-rects:0.

bug 1638835: Maybe Win8 has the same problem. I still wanted to install it.

Comment 18

[Darkspirit]

Intel HD Graphics 630 (0x8086 0x5912 21.20.16.4508, 2016-08-27, 2560x1440)
Autoscrolling this page with Direct3D 11 (bug 1638469) up and down stutters and there is checkerboarding at the top when scrolling up.
WebRender ("first bad" with partial present disabled) scrolls smoothly.

Comment 19

[Sotaro Ikeda [:sotaro]]

I am going to take a look.

Comment 20

[Darkspirit]

Firefox on Win7 should require DWM (Aero) only for partial present (instead of blocking WebRender completely) and Firefox graphics should be reinitialized when the user changes the Windows theme: When switching from Aero to non-Aero, wrong window buttons are shown and the corner looks incorrectly cut out until you restart Firefox.

Comment 21

[Sotaro Ikeda [:sotaro]]

Bug 1638469 disable WebRender during initialization. Then, it does not handle enabling/disabling DWM dynamically. Then the problem still exist on the following STR

• [1] Confirm Aero is enabled
• [2] Start Firefox with WebRender
• [3] Disable Aero by changing window theme
• [4] Switch between two Firefox windows

Comment 22

[Sotaro Ikeda [:sotaro]]

gfxVars::DwmCompositionEnabled() is dynamically updated in the following.

• https://searchfox.org/mozilla-central/rev/bc3600def806859c31b2c7ac06e3d69271052a89/widget/windows/nsWindow.cpp#6114

Comment 23

[Sotaro Ikeda [:sotaro]]

Attachment: Bug 1637497 - Disable partial present dynamically when Dwm is disabled

Comment 24

[Sotaro Ikeda [:sotaro]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=a1fecb58adbe6ac273ea39fd3027c298bc08e2d1

Comment 25

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e9507c0042be
Disable partial present dynamically when Dwm is disabled r=jrmuizel

Comment 26

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/e9507c0042be

Comment 27

[Jeff Muizelaar [:jrmuizel]]

Sotaro, I meant to write this in the review comments but it looks like I didn't. Do you mind adding a comment around:

   mFullRender = true;
  }

describing why it is necessary?

Comment 28

[Sotaro Ikeda [:sotaro]]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #27)

Sotaro, I meant to write this in the review comments but it looks like I didn't. Do you mind adding a comment around:

   mFullRender = true;
  }

describing why it is necessary?

Bug 1642834 is for adding a comment. But Bug 1642839 seems like a better fix.

Comment 29

[Rares Doghi, Desktop QA]

This issue is verified as fixed in Beta 79.0b2 on Windows 7.