On 25/04/17 01:54 AM, Mario Kleiner wrote:
Make sure we do not program a hw pageflip inside vblank 'n' iff the atomic flip is comitted while inside the same vblank 'n'. We must defer such a flip by one refresh cycle to vblank 'n+1', unless this is a DRM_MODE_PAGE_FLIP_ASYNC async pageflip, which must always execute as soon as possible.
Without this, pageflips programmed via X11 GLX_OML_sync_control extensions glXSwapBuffersMscOML(..., target_msc, ...); call and/or via DRI3/Present PresentPixmap(..., target_msc, ...); request will complete one vblank too early whenever target_msc > current_msc + 1, ie. more than 1 vblank in the future. In such a case, the call of the pageflip ioctl() would be triggered by a queued drmWaitVblank() vblank event, which itself gets dispatched inside the vblank one frame before the target_msc vblank.
Testing with this patch does no longer show any problems with OML_sync_control swap scheduling or flip completion timestamps. Tested on R9 380 Tonga.
v2: Add acked/r-b by Harry and Michel. v3: Feedback from Andrey: Must not wait an extra frame for DRM_MODE_PAGE_FLIP_ASYNC flips.
Signed-off-by: Mario Kleiner mario.kleiner.de@gmail.com Acked-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Michel Dänzer michel.daenzer@amd.com
This patch and v2 of patch 1 pushed to the internal amd-staging-4.9 branch, thanks!