Currently, on a handful of ASICs. We allow the framebuffer for a given plane to exist in either VRAM or GTT. However, if the plane's new framebuffer is in a different memory domain than it's previous framebuffer, flipping between them can cause the screen to flicker. So, to fix this, don't perform an immediate flip in the aforementioned case.

Cc: stable@vger.kernel.org Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2354 Fixes: 81d0bcf99009 ("drm/amdgpu: make display pinning more flexible (v2)") Signed-off-by: Hamza Mahfooz hamza.mahfooz@amd.com --- v2: make a number of clarifications to the commit message and drop locking. --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)

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 da3045fdcb6d..fd1b323f0e85 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -7897,6 +7897,13 @@ static void amdgpu_dm_commit_cursors(struct drm_atomic_state *state) amdgpu_dm_plane_handle_cursor_update(plane, old_plane_state); }

+static inline uint32_t get_mem_type(struct drm_framebuffer *fb) +{ + struct amdgpu_bo *abo = gem_to_amdgpu_bo(fb->obj[0]); + + return abo->tbo.resource ? abo->tbo.resource->mem_type : 0; +} + static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, struct dc_state *dc_state, struct drm_device *dev, @@ -7916,6 +7923,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, to_dm_crtc_state(drm_atomic_get_old_crtc_state(state, pcrtc)); int planes_count = 0, vpos, hpos; unsigned long flags; + uint32_t mem_type; u32 target_vblank, last_flip_vblank; bool vrr_active = amdgpu_dm_crtc_vrr_active(acrtc_state); bool cursor_update = false; @@ -8035,13 +8043,17 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, } }

+ mem_type = get_mem_type(old_plane_state->fb); + /* * Only allow immediate flips for fast updates that don't - * change FB pitch, DCC state, rotation or mirroing. + * change memory domain, FB pitch, DCC state, rotation or + * mirroring. */ bundle->flip_addrs[planes_count].flip_immediate = crtc->state->async_flip && - acrtc_state->update_type == UPDATE_TYPE_FAST; + acrtc_state->update_type == UPDATE_TYPE_FAST && + (!mem_type || get_mem_type(fb) == mem_type);

timestamp_ns = ktime_get_ns(); bundle->flip_addrs[planes_count].flip_timestamp_in_us = div_u64(timestamp_ns, 1000);