On 11/10/2015 05:00 PM, Thierry Reding wrote:
On Tue, Nov 10, 2015 at 03:54:52PM +0100, Mario Kleiner wrote:From: Daniel Vetter <daniel.vetter@xxxxxxxx> 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@xxxxxxxxx> 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@xxxxxxxxxx> Date: Wed Aug 12 17:00:31 2015 +0200 drm/irq: Make pipe unsigned and name consistent Trigering 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@xxxxxxxxxx> Cc: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> Cc: Ben Skeggs <bskeggs@xxxxxxxxxx> Cc: Ilia Mirkin <imirkin@xxxxxxxxxxxx> 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 avoidng trouble in drm_handle_vblank_events(). - Remove dead code and spelling fix. v3 (mario): Add a signed-off-by and cc stable tag per Ilja's advice. Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> (v1) Reviewed-by: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> (v2/v3) Signed-off-by: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v4.3 --- drivers/gpu/drm/drm_irq.c | 54 ++++++++++++++++++++++++++++++- drivers/gpu/drm/nouveau/nouveau_display.c | 19 ++++++----- include/drm/drmP.h | 4 +++ 3 files changed, 68 insertions(+), 9 deletions(-)This looks good to me. Let me clean this up a little and submit it to Dave. Thierry
Btw., if somebody has a functional old card for testing this, it should be easy to verify if it works on pre-nv50. If it would not work it would deliver the pageflip event 1 frame delayed, so at least on standard nouveau + default DRI2 + default double-buffering the rate for a tight loop of page-flipped swaps should go down to 30 fps on a 60 Hz display, quite noticeable. Afaik we also have Piglit tests for OML_sync_control which would likely fail if this would be broken.
Oh and if someone has tips on how to resurrect an old nv-40 PC (booted with BIOS only) graphics card in a MacPro (EFI boot), i wouldn't mind hearing them. It would be nice to still be able to use that card for testing.
thanks, -mario _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
