From: James Lin <[email protected]> [Why] The cursor-mode re-evaluation added to dm_crtc_get_cursor_mode() also checks the cursor plane's own destination rectangle. The crtc_x/y/w/h check lives in the per-plane loop, which only flags the cursor plane via cursor_changed and does not skip it, so the check fires whenever the cursor itself moves.
flip-vs-cursor-legacy (kms_cursor_legacy) issues a stream of legacy cursor moves and requires each to land on the fast path within a single vblank. With the position check, every cursor move now sets consider_mode_change and defeats the early return, forcing the full cursor-mode evaluation. A legacy cursor move is a cursor-only commit: the underlying planes are not in the atomic state, so the coverage loop (for_each_oldnew_plane_in_descending_zpos walks only planes in the state) sees nothing covering the CRTC, evaluates entire_crtc_covered as false, and misclassifies the cursor mode as OVERLAY on a fully-covered screen. That spurious NATIVE->OVERLAY transition makes should_reset_plane() return true (lock_and_validation_needed), pulls all CRTC planes into the commit, and - because amdgpu_dm_plane_atomic_async_check() rejects async updates in overlay mode - permanently knocks later cursor updates off the async fast path. Each cursor move becomes a full atomic commit with DC global validation, serialized against the page flip, so cursor updates no longer fit in one vblank and flip-vs-cursor-legacy fails / times out [How] The cursor mode is a function of the underlying planes' coverage and properties, not of the cursor's position, so cursor movement can never change the correct mode. Restrict the destination-rectangle check to non-cursor planes. A move/resize of an underlying plane (the case the original change targets, e.g. amd_cursor_overlay@non-full) still re-evaluates the mode correctly, while pure cursor movement returns to the fast path. Reviewed-by: ChiaHsuan (Tom) Chung <[email protected]> Signed-off-by: James Lin <[email protected]> Signed-off-by: George Zhang <[email protected]> --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 27 +++++++++++++------ 1 file changed, 19 insertions(+), 8 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 d184cc4de693..2cdc297e6cab 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6656,15 +6656,26 @@ static int dm_crtc_get_cursor_mode(struct amdgpu_device *adev, } /* - * A plane moving or resizing (without a scale change) changes how - * much of the CRTC it covers. This can create/remove holes under - * the cursor and thus flip the required cursor mode (native vs - * overlay), so the destination rect must be re-evaluated too. + * A non-cursor plane moving or resizing (without a scale change) + * changes how much of the CRTC it covers. This can create or + * remove a hole under the cursor and thus flip the required + * cursor mode (native vs overlay), so its destination rect must + * be re-evaluated too. + * + * The cursor plane itself is deliberately excluded: the cursor + * mode depends on the underlying planes' coverage, not on the + * cursor's position (see the entire_crtc_covered logic below). + * Triggering on cursor movement would force every legacy cursor + * update off its fast path, and in a cursor-only commit - where + * the underlying planes are not part of the state - the coverage + * loop would see no covering plane and misevaluate the mode as + * overlay, regressing flip-vs-cursor-legacy. */ - if (old_plane_state->crtc_x != plane_state->crtc_x || - old_plane_state->crtc_y != plane_state->crtc_y || - old_plane_state->crtc_w != plane_state->crtc_w || - old_plane_state->crtc_h != plane_state->crtc_h) { + if (plane->type != DRM_PLANE_TYPE_CURSOR && + (old_plane_state->crtc_x != plane_state->crtc_x || + old_plane_state->crtc_y != plane_state->crtc_y || + old_plane_state->crtc_w != plane_state->crtc_w || + old_plane_state->crtc_h != plane_state->crtc_h)) { consider_mode_change = true; break; } -- 2.55.0
