From caff0e6654377b623e37922d084b1a33aa9d44d7 Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas Date: Fri, 2 Aug 2019 10:45:11 -0400 Subject: [PATCH] drm/amd/display: Block immediate flips for non-fast updates [Why] Underflow can occur in the case where we change buffer pitch, DCC state, rotation or mirroring for a plane while also performing an immediate flip. It can also generate a p-state warning stack trace on DCN1 which is typically observed during the cursor handler pipe locking because of how frequent cursor updates can occur. [How] Store the update type on each CRTC - every plane will have access to the CRTC state if it's flipping. If the update type is not UPDATE_TYPE_FAST then the immediate flip should be disallowed. No changes to the target vblank sequencing need to be done, we just need to ensure that the surface registers do a double buffered update. Signed-off-by: Nicholas Kazlauskas Reviewed-by: David Francis Signed-off-by: Alex Deucher --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 16 +++++++++++++++- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 1 + 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 0432c312a20d..0bcb7662e2d9 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5723,8 +5723,14 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, bundle->surface_updates[planes_count].plane_info = &bundle->plane_infos[planes_count]; + /* + * Only allow immediate flips for fast updates that don't + * change FB pitch, DCC state, rotation or mirroing. + */ bundle->flip_addrs[planes_count].flip_immediate = - (crtc->state->pageflip_flags & DRM_MODE_PAGE_FLIP_ASYNC) != 0; + (crtc->state->pageflip_flags & + DRM_MODE_PAGE_FLIP_ASYNC) != 0 && + acrtc_state->update_type == UPDATE_TYPE_FAST; timestamp_ns = ktime_get_ns(); bundle->flip_addrs[planes_count].flip_timestamp_in_us = div_u64(timestamp_ns, 1000); @@ -7400,6 +7406,14 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev, } } + /* Store the overall update type for use later in atomic check. */ + for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) { + struct dm_crtc_state *dm_new_crtc_state = + to_dm_crtc_state(new_crtc_state); + + dm_new_crtc_state->update_type = (int)overall_update_type; + } + /* Must be success */ WARN_ON(ret); return ret; diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h index 35bee77def3b..c8c525a2b505 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h @@ -310,6 +310,7 @@ struct dm_crtc_state { bool cm_has_degamma; bool cm_is_degamma_srgb; + int update_type; int active_planes; bool interrupts_enabled;