999663 - ClientTiledThebesLayer clips sync-scrolling subframes to the wrong critical displayport

Status: RESOLVED DUPLICATE of bug 1016558

(Core :: Graphics: Layers, defect)

Description

[Kartikaya Gupta (email:[e-mail])]

This is a follow-up bug for bug 993554 to remove the workaround added there and to fix the issue properly. Bug 993554 comment 10 describes the issue in some detail. As far as we know this is only an issue on Fennec because Fennec doesn't set displayports on subframes while B2G does. Also on B2G tiled layers are only created for layers that are scrollable so this shouldn't happen on B2G layers that have CSS transforms so as to simulate sync scrolling.

A better fix for Fennec might be to implement the last approach described in bug 993554 comment 10, so that layers for sync scrolling subframes in Fennec are not tiled, and use ClientThebesLayer instead of ClientTiledThebesLayer.

Comment 1

[Chris Lord [:cwiiis]]

To be honest, I think the best solution here is to invest the time in switching fennec over to the APZC - maintaining both is getting tiresome and there's a lot of code we could remove if we did.

I don't think it's a good idea to use non-tiled layers on Android, to avoid driver issues. Do we have a bug that covers switching Android to APZC? (I searched and couldn't find one)

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Yup, bug 776030.

Comment 3

[Chris Lord [:cwiiis]]

huh, a search for 'fennec async' didn't turn that up. Thanks!

Comment 4

[Chris Lord [:cwiiis]]

Unassigning, I think this should just block on bug 776030 and have done with it, and I'm not the best person to fix this regardless.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

Actually I think bug 1016558 fixed this somewhat correctly and bug 1017680 removed the ifdef block. Bug 1018387 has some follow-up fixes as well.