drm/amd/display: don't re-evaluate cursor mode on cursor plane movement

[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 <chiahsuan.chung@amd.com>
Signed-off-by: James Lin <PingLei.Lin@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions