> -----Original Message----- > From: Mario Kleiner [mailto:mario.kleiner.de at gmail.com] > Sent: Monday, April 24, 2017 12:54 PM > To: dri-devel at lists.freedesktop.org > Cc: amd-gfx at lists.freedesktop.org; Grodzovsky, Andrey; > mario.kleiner.de at gmail.com; Wentland, Harry; Deucher, Alexander; > Daenzer, Michel > Subject: [PATCH 2/2] drm/amd/display: Prevent premature pageflip when > comitting in vblank. (v3) > > 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 at gmail.com> > Acked-by: Harry Wentland <harry.wentland at amd.com> > Reviewed-by: Michel Dänzer <michel.daenzer at amd.com> > > Cc: Harry Wentland <Harry.Wentland at amd.com> > Cc: Alex Deucher <alexander.deucher at amd.com> > Cc: Michel Dänzer <michel.daenzer at amd.com> > --- > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c | 20 > ++++++++++---------- > 1 file changed, 10 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c > index 086a842..82b2ce6 100644 > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c > @@ -2460,6 +2460,9 @@ static void amdgpu_dm_do_flip( > struct amdgpu_device *adev = crtc->dev->dev_private; > bool async_flip = (acrtc->flip_flags & > DRM_MODE_PAGE_FLIP_ASYNC) != 0; > > + /* Prepare wait for target vblank early - before the fence-waits */ > + target_vblank = target - drm_crtc_vblank_count(crtc) + > + amdgpu_get_vblank_counter_kms(crtc->dev, acrtc- > >crtc_id); > > /*TODO This might fail and hence better not used, wait > * explicitly on fences instead > @@ -2478,13 +2481,9 @@ static void amdgpu_dm_do_flip( > > amdgpu_bo_unreserve(abo); > > - /* Wait for target vblank */ > /* Wait until we're out of the vertical blank period before the one > * targeted by the flip > */ > - target_vblank = target - drm_crtc_vblank_count(crtc) + > - amdgpu_get_vblank_counter_kms(crtc->dev, acrtc- > >crtc_id); > - > while ((acrtc->enabled && > (amdgpu_get_crtc_scanoutpos(adev->ddev, acrtc->crtc_id, > 0, > &vpos, &hpos, NULL, NULL, > @@ -2760,14 +2759,15 @@ void amdgpu_dm_atomic_commit_tail( > pflip_needed = !state->allow_modeset; > > if (pflip_needed) { > + wait_for_vblank = > + acrtc->flip_flags & > DRM_MODE_PAGE_FLIP_ASYNC ? > + false : true; > + > amdgpu_dm_do_flip( > - crtc, > - fb, > - drm_crtc_vblank_count(crtc)); > + crtc, > + fb, > + drm_crtc_vblank_count(crtc) + > wait_for_vblank); > > - wait_for_vblank = > - acrtc->flip_flags & > DRM_MODE_PAGE_FLIP_ASYNC ? > - false : true; > /*clean up the flags for next usage*/ > acrtc->flip_flags = 0; > } > -- > 2.7.4 Reviewed-by: Andrey Grodzovsky <Andrey.Grodzovsky at amd.com>
