1265926 - Screen tearing on Mac OS 10.11.5 Beta using second screen

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[u279076]

I'm experiencing screen tearing on MacOS 10.11.5 Beta (15F18b). I'm using Firefox Nightly 48.0a1 on a Macbook Pro (Retina, 13-inch, Late 2013) with the Firefox window on secondary screen (Dell 1080p LCD monitor connected to HDMI via Thunderbolt).

You can see the effect here:
https://youtu.be/_XbMfVP_Bpw

I'm not sure what is causing it as the issue is intermittent but I do see it at least a few times a day. I first noticed it a few days ago but it could have been starting earlier. I'm not sure if it's related to the OS X Beta or a Firefox Nightly change.

Here's a copy of about:support:
Asynchronous Pan/Zoom	wheel input enabled
Device ID	0x0a2e
GPU Accelerated Windows	1/1 OpenGL (OMTC)
Supports Hardware H264 Decoding	Yes
Vendor ID	0x8086
WebGL Renderer	Intel Inc. -- Intel Iris OpenGL Engine
windowLayerManagerRemote	true
AzureCanvasAccelerated	1
AzureCanvasBackend	skia
AzureContentBackend	skia
AzureFallbackCanvasBackend	none

I'll try running for a couple days with gfx.content.azure.backends set to cg and see if it comes back.

Comment 1

[u279076]

Mason, CCing you just as an FYI. I'm not sure this is Skia related as of yet.

Comment 2

[u279076]

(In reply to Anthony Hughes (:ashughes) [GFX][QA][Mentor] from comment #0)
> I'll try running for a couple days with gfx.content.azure.backends set to cg and see if it comes back.

I've not seen this issue in the last couple of days, however I've kept my Nightly up to date and received a new OS X Beta since. I'm going to reset gfx.content.azure.backends to default and continue dogfooding this next week to see if the issue returns.

Comment 3

[u279076]

It's been a few more days since switching back to Skia and I've not yet reproduced this issue. I'm going to resolve this bug as WORKSFORME for now. It's purely conjecture but I guess this could have been a bug in the previous Mac OS 10.11 Beta. I will reopen this bug report if I see the issue again.

Comment 4

[u279076]

I managed to get the issue to come back and it's happening the Skia turned off so it's definitely not a Skia bug. I'm also seeing the screen tearing in other apps like the OS X Terminal. I think this is more than likely a bug in OS X Beta and so I've escalated this to bugreport.apple.com.