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 at 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 at 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 at nvidia.com> >> 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 at nvidia.com> >> Cc: Mario Kleiner <mario.kleiner.de at gmail.com> >> Cc: Ben Skeggs <bskeggs at redhat.com> >> Cc: Ilia Mirkin <imirkin at 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 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 at intel.com> >> (v1) Reviewed-by: Mario Kleiner <mario.kleiner.de at gmail.com> >> (v2/v3) Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com> >> >> Cc: stable at vger.kernel.org # 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
