Am 20.04.23 um 15:44 schrieb Hamza Mahfooz:
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@xxxxxxxxxxxxxxx
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@xxxxxxx>
---
v2: make a number of clarifications to the commit message and drop
locking.
v3: use a stronger check
---
.../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 dfcb9815b5a8..875111340203 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7900,6 +7900,13 @@ 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,
@@ -7919,6 +7926,7 @@ 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;
@@ -8040,13 +8048,17 @@ 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;
I think you can actually drop checking mem_type here.
When the FB has no backing store, we actually don't have anything to
scan out. In this case flickering is the least of your problems :)
Christian
timestamp_ns = ktime_get_ns();
bundle->flip_addrs[planes_count].flip_timestamp_in_us = div_u64(timestamp_ns, 1000);
