[PATCH 3/8] drm/i915/psr: Disable linked plane sel fetch as well

["Jouni Högander" <jouni.hogander@intel.com>]

Currently we are not setting linked plane selective area when selective
fetch is about to be disabled for the UV plane. Fix this by simplifying the
loop by just handling plane selective fetch disable and area setting same
way.

Also set the update_planes bit based on comparing old and new plane
selective fetch area. This way both the plane and its linked Y plane are
updated only when their selective fetch area changed.

Fixes: a4f477e6ac17 ("drm/i915/psr: Add proper handling for disabling sel fetch for planes")
Cc: <stable@vger.kernel.org> # v6.8+
Assisted-by: GitHub-Copilot:claude-opus-5
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 27 ++++++++++++------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index a9e9215200015..f2ec7b0e0668c 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -3065,21 +3065,14 @@ int intel_psr2_sel_fetch_update(struct intel_atomic_state *state,
 
 		inter = crtc_state->psr2_su_area;
 		sel_fetch_area = &new_plane_state->psr2_sel_fetch_area;
-		if (!drm_rect_intersect(&inter, &new_plane_state->uapi.dst)) {
-			/*
-			 * if plane sel fetch was previously enabled ->
-			 * disable it
-			 */
-			if (drm_rect_height(&old_plane_state->psr2_sel_fetch_area) > 0)
-				crtc_state->update_planes |= BIT(plane->id);
-
-			continue;
+		if (drm_rect_intersect(&inter, &new_plane_state->uapi.dst)) {
+			sel_fetch_area->y1 = inter.y1 - new_plane_state->uapi.dst.y1;
+			sel_fetch_area->y2 = inter.y2 - new_plane_state->uapi.dst.y1;
 		}
 
-		sel_fetch_area = &new_plane_state->psr2_sel_fetch_area;
-		sel_fetch_area->y1 = inter.y1 - new_plane_state->uapi.dst.y1;
-		sel_fetch_area->y2 = inter.y2 - new_plane_state->uapi.dst.y1;
-		crtc_state->update_planes |= BIT(plane->id);
+		if (!drm_rect_equals(&old_plane_state->psr2_sel_fetch_area,
+				     sel_fetch_area))
+			crtc_state->update_planes |= BIT(plane->id);
 
 		/*
 		 * Sel_fetch_area is calculated for UV plane. Use
@@ -3087,16 +3080,22 @@ int intel_psr2_sel_fetch_update(struct intel_atomic_state *state,
 		 */
 		if (linked) {
 			struct intel_plane_state *linked_new_plane_state;
+			struct intel_plane_state *linked_old_plane_state;
 			struct drm_rect *linked_sel_fetch_area;
 
 			linked_new_plane_state = intel_atomic_get_new_plane_state(state, linked);
 			if (!linked_new_plane_state)
 				return -EINVAL;
 
+			linked_old_plane_state = intel_atomic_get_old_plane_state(state, linked);
+
 			linked_sel_fetch_area = &linked_new_plane_state->psr2_sel_fetch_area;
 			linked_sel_fetch_area->y1 = sel_fetch_area->y1;
 			linked_sel_fetch_area->y2 = sel_fetch_area->y2;
-			crtc_state->update_planes |= BIT(linked->id);
+
+			if (!drm_rect_equals(&linked_old_plane_state->psr2_sel_fetch_area,
+					     linked_sel_fetch_area))
+				crtc_state->update_planes |= BIT(linked->id);
 		}
 	}
 
-- 
2.43.0