717714 - WebGL stops working if the GFX card goes away

Status: NEW

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

Description

[Dave Townsend [:mossop]]

My laptop is fun. It has a dock that connects with an additional GFX card to drive the main monitor.

If I start Firefox with the dock connected then webgl works.

If I start Firefox without the dock connected then webgl works.

If I start Firefox with the dock connected then disconnect the dock then webgl takes a while then fails, "Hmm. While your browser seems to support WebGL, it is disabled or unavailable. If possible, please ensure that you are running the latest drivers for your video card". Re-connecting the dock doesn't help, I have to restart Firefox after that.

If I start Firefox without the dock connected then connect the dock then webgl continues to work. Disconnecting the dock after this and webgl continues to work.


My vague hand-wavy guess is that the first time I use webgl it selects a graphics card and continues to attempt to use that for the lifetime of the app. If that graphics card is no longer present then webgl stops working and never works again, even though it could presumably look and find a different graphics card to use.

Comment 1

[Benoit Jacob [:bjacob] (mostly away)]

The first thing to find out is whether this is an issue with blacklisting or with actual failure to get a GL context. Can you set webgl.force-enabled=true and see if problems persist?

Comment 2

[Dave Townsend [:mossop]]

Progress, of a sort. With webgl.force-enabled true it now crashes when I undock and attempt to use webgl:

https://crash-stats.mozilla.com/report/index/bp-7e847874-035e-4102-a59a-8052c2120112
https://crash-stats.mozilla.com/report/index/bp-67d7256e-1e25-456e-97f7-5c7972120112
https://crash-stats.mozilla.com/report/index/bp-87ec5d0d-3dbf-4eb0-b7a5-1644f2120112