Apparently pre-nv50 pageflip events happen before the actual vblank
period. Therefore that functionality got semi-disabled in
commit af4870e406
Author: Mario Kleiner <mario.kleiner.de@gmail.com>
Date: Tue May 13 00:42:08 2014 +0200
drm/nouveau/kms/nv04-nv40: fix pageflip events via special case.
Unfortunately that hack got uprooted in
commit cc1ef118fc
Author: Thierry Reding <treding@nvidia.com>
Date: Wed Aug 12 17:00:31 2015 +0200
drm/irq: Make pipe unsigned and name consistent
Triggering a warning when trying to sample the vblank timestamp for a
non-existing pipe. There's a few ways to fix this:
- Open-code the old behaviour, which just enshrines this slight
breakage of the userspace ABI.
- Revert Mario's commit and again inflict broken timestamps, again not
pretty.
- Fix this for real by delaying the pageflip TS until the next vblank
interrupt, thereby making it accurate.
This patch implements the third option. Since having a page flip
interrupt that happens when the pageflip gets armed and not when it
completes in the next vblank seems to be fairly common (older i915 hw
works very similarly) create a new helper to arm vblank events for
such drivers.
v2 (Mario Kleiner):
- Fix function prototypes in drmP.h
- Add missing vblank_put() for pageflip completion without
pageflip event.
- Initialize sequence number for queued pageflip event to avoid
trouble in drm_handle_vblank_events().
- Remove dead code and spelling fix.
v3 (Mario Kleiner):
- Add a signed-off-by and cc stable tag per Ilja's advice.
v4 (Thierry Reding):
- Fix kerneldoc typo, discovered by Michel Dänzer
- Rearrange tags and changelog
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=106431
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: stable@vger.kernel.org # v4.3
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
bbc8764f80