Created attachment 117492 [details]
example application
With GL applications if the render time is > 1 frame (> 2 for more reliable
triggering) and the window is fullscreen, I have flickering betweeen old and
new frames.
Attached is an example application that if run fullscreen and sufficiently slow
exhibits the problem. The quad is supposed to rotate when you press space, but
the first moments you get some combination of the two rotated quads.
Workarounds include:
- making the window not fullscreen.
- use xcompmgr to enable compositing.
- using vblank_mode=0
Hardware:
Sapphire R9 285 Dual-X OC 2 GB (TONGA)
Software
kernel from adg5f/linux drm-next-4.3-wip commit
88a7d7fa964602514496223639c4e0432fbd457b (also occurs on 4.2-rc4)
drm, mesa from agd5f/... amdgpu branches
xf86-video-amdgpu from master
Xserver 1.17.2
My window manager is XMonad, which is a tiling window manager without
compositing.
The attached Xorg.0.log contains some warnings:
(WW) AMDGPU(0): amdgpu_dri2_flip_event_handler: Pageflip completion event has
impossible msc 189694 < target_msc 189695
However, running the example application or my original application does not
(consistently) generate those warnings when run.