On 11/09/2015 02:02 PM, Ilia Mirkin wrote:
On Mon, Nov 9, 2015 at 7:57 AM, Mario Kleiner mario.kleiner.de@gmail.com wrote:
From: Daniel Vetter daniel.vetter@ffwll.ch
Apparently pre-nv50 pageflip events happen before the actual vblank period. Therefore that functionality got semi-disabled in
commit af4870e406126b7ac0ae7c7ce5751f25ebe60f28 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 cc1ef118fc099295ae6aabbacc8af94d8d8885eb Author: Thierry Reding treding@nvidia.com Date: Wed Aug 12 17:00:31 2015 +0200
drm/irq: Make pipe unsigned and name consistentTrigering 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.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=106431 Cc: Thierry Reding treding@nvidia.com Cc: Mario Kleiner mario.kleiner.de@gmail.com Cc: Ben Skeggs bskeggs@redhat.com Cc: Ilia Mirkin imirkin@alum.mit.edu
v2 (mario): Integrate my own review comments into Daniels patch. - 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.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Reviewed-by: Mario Kleiner mario.kleiner.de@gmail.com
Without commenting on the actual patch, a few points of procedure:
(a) If you're sending the patch, you're supposed to add your Signed-off-by. So you'd keep Daniel's and add yours.
I thought my tiny fixes didn't warrant adding a signed off by myself, but if that was wrong, consider it added:
v2: Signed-off-by: Mario Kleiner mario.kleiner.de@gmail.com
(b) Since this is triggering warns for real people in real situations, tack on a
Cc: stable@vger.kernel.org # v4.3
Ah, sorry, this is already a problem in a released kernel? I thought this was something new and so far only for drm-next.
ciao, -mario
Cheers,
-ilia