887975 - Flickering when panning content and the richgrid on the start UI

Status: RESOLVED FIXED

(Core :: Graphics: Layers, defect)

Description

[Jonathan Wilde [:jwilde]]

When you pan the start UI, the richgrid will periodically disappear. See attached video.

Comment 1

[Brian R. Bondy [:bbondy]]

This is all changing with the async pan zoom controller, we should re-evaluate if this is a bug when that lands and is switched on.

Comment 2

[Jonathan Wilde [:jwilde]]

Attachment: video of flickering

Comment 3

[Jim Mathies [:jimm]]

I'm pretty sure this is in layers code. If we can assure ourselves it's not in the front end we should update the product/component so gfx folks see it.

jwilde, can you reproduce this in mc tip with "gfx.direct2d.disabled" set to true?

Comment 4

[Jonathan Wilde [:jwilde]]

Updated to mc tip and clobbered/rebuilt:

Without gfx.direct2d.disabled: flicker.
With gfx.direct2d.disabled: no flicker.

Comment 7

[Milan Sreckovic [:milan] (needinfo for best results)]

Bas, thoughts?

Comment 8

[Jim Mathies [:jimm]]

reproducible on this page:

https://developer.mozilla.org/en-US/docs/HTML/HTML_Elements/textarea#HTML_Content

down near the bottom where the page has an embedded iframe with a text area in it.

Comment 9

[Bas Schouten (:bas.schouten)]

(In reply to Milan Sreckovic [:milan] from comment #7)
> Bas, thoughts?

Hrm, I'm not sure what the behavior of Metro is at the moment with Direct2D disabled, definitely looks like a graphics problem but I have no initial idea on what the cause is. Also no Windows 8 machine with me in SF to try and debug this.

Comment 10

[Marco Mucci [:MarcoM]]

Hi Bas, we have Metro team members in SF who could show you on a Win 8 device.

Comment 11

[Bas Schouten (:bas.schouten)]

(In reply to Marco Mucci [:MarcoM] from comment #10)
> Hi Bas, we have Metro team members in SF who could show you on a Win 8
> device.

I'd be more than happy to look at it, I'm at the 7th floor on Elika's desk. I can probably give some pointers as well but I doubt I can do significant debugging right now.

Comment 12

[Marco Mucci [:MarcoM]]

Hi Ally, can you see Comments 9,10,11.

Comment 13

[Allison Naaktgeboren :ally]

Bas, headed your way

Comment 14

[Bas Schouten (:bas.schouten)]

Had a look at Ally's machine. ContentHostDoubleBuffered::UpdateThebes and ThebesLayerBuffer::BeginPaint is kind of where all the mess of moving the buffer around in memory and making sure front and back buffer are in sync happens. This bug looks to me like sometimes the syncing is not correct (i.e. the content in the middle, which is not being redrawn, is in one of the buffers but not in the other). It's particularly interesting that as you scroll it can re-appear, meaning it either gets redrawn or we're just ending up with 'the other' buffer of the swap chain where the content is still present.

Comment 15

[Marco Mucci [:MarcoM]]

Thanks for looking into it Bas.  Anything you can do to help you would great.

Comment 18

[Jim Mathies [:jimm]]

on latest tip (Wed Jul 24 05:36:15 2013 PDT), I can't reproduce.

Comment 19

[Jim Mathies [:jimm]]

Oddly enough, this is now back with apz enabled.

Comment 20

[Matt Brubeck (:mbrubeck)]

I'm also seeing this again with APZC disabled, though for a while it went away.

Comment 21

[juan becerra [:juanb]]

On machines with Atom processors the tiles disappear when you pan left or right.

Comment 22

[Brian R. Bondy [:bbondy]]

I get that sometime with my sony vaio which is intel

Comment 23

[Milan Sreckovic [:milan] (needinfo for best results)]

Does it work with the patch from bug 900742?

Comment 24

[Jim Mathies [:jimm]]

(In reply to Milan Sreckovic [:milan] from comment #23)
> Does it work with the patch from bug 900742?

Doesn't look like an event related patch like that would help but I can take it for a spin to see.

One interesting thing I noticed about this today, when we scroll via the mouse wheel we don't see a flicker. Mouse wheel translates into scrollBy calls on the start ui panel. Not sure why it would not reproduce in that case, but reproduce when dragging the scrollbar with the mouse to scroll.

Comment 25

[Matt Brubeck (:mbrubeck)]

Attachment: work-around: remove "watermark" background image

I discovered today that removing the background image ("Firefox" watermark) from the start page fixes the flickering on my system.  Is this an acceptable band-aid until we can find a fix or workaround that lets us scroll correctly with the image in place?

Comment 26

[Yuan Wang(:Yuan) – Mobile Firefox Design Lead]

That's acceptable with me. The improved performance is definitely a bigger win here.

Comment 28

[Jim Mathies [:jimm]]

We should spin this patch off into a metro bug so the gfx bug stays open (or change up this bug and file a new gfx bug.) We still want a bug open on the compositor / layers painting problem. (I've seen this occasionally in content as well.)

Comment 29

[Brian R. Bondy [:bbondy]]

Let's spin a new gfx bug for that and CC kats, that issue will probably be one he, or BenWa has to fix. It would be ideal if we could use jing to capture a short video of the problem happening on content. It's just a software that you install, press a button to record your screen, and it gives you a link you can use online.

Comment 30

[Brian R. Bondy [:bbondy]]

Jim if you can reproduce that easily you can also try tweaking some of these prefs:
http://mxr.mozilla.org/mozilla-central/source/gfx/layers/ipc/AsyncPanZoomController.cpp#146

Comment 31

[Allison Naaktgeboren :ally]

Comment on attachment 786642 [details] [diff] [review]
work-around: remove "watermark" background image

Review of attachment 786642 [details] [diff] [review]:
-----------------------------------------------------------------

Does what it says on the box. Though I hope we get a real gfx fix soon. :)

Comment 32

[Matt Brubeck (:mbrubeck)]

https://hg.mozilla.org/integration/fx-team/rev/4e2e139c6b83

As discussed above, we'll close this bug and open a new bug to track the underlying graphics or layout issue.

Comment 33

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/4e2e139c6b83

Comment 34

[Jim Mathies [:jimm]]

(In reply to Matt Brubeck (:mbrubeck) from comment #32)
> https://hg.mozilla.org/integration/fx-team/rev/4e2e139c6b83
> 
> As discussed above, we'll close this bug and open a new bug to track the
> underlying graphics or layout issue.

Did we file a new bug yet?

Comment 35

[Jim Mathies [:jimm]]

(In reply to Jim Mathies [:jimm] from comment #34)
> (In reply to Matt Brubeck (:mbrubeck) from comment #32)
> > https://hg.mozilla.org/integration/fx-team/rev/4e2e139c6b83
> > 
> > As discussed above, we'll close this bug and open a new bug to track the
> > underlying graphics or layout issue.
> 
> Did we file a new bug yet?

filed bug 903421.