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@gmail.com Acked-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Michel Dänzer michel.daenzer@amd.com
Cc: Harry Wentland Harry.Wentland@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Michel Dänzer michel.daenzer@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; }
-----Original Message----- From: Mario Kleiner [mailto:mario.kleiner.de@gmail.com] Sent: Monday, April 24, 2017 12:54 PM To: dri-devel@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org; Grodzovsky, Andrey; mario.kleiner.de@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@gmail.com Acked-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Michel Dänzer michel.daenzer@amd.com
Cc: Harry Wentland Harry.Wentland@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Michel Dänzer michel.daenzer@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@amd.com
On 25/04/17 01:54 AM, Mario Kleiner wrote:
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@gmail.com Acked-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Michel Dänzer michel.daenzer@amd.com
This patch and v2 of patch 1 pushed to the internal amd-staging-4.9 branch, thanks!
dri-devel@lists.freedesktop.org
-
Grodzovsky, Andrey -
Mario Kleiner -
Michel Dänzer