[PATCH 8/8] drm/i915/psr: Don't clip plane state destination rectangle

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

clip_area_update() uses drm_rect_intersect which modifies passed r1
rectangle. Early transport alignment passes the cursor uapi.dst rectangle
to clip_area_update, so the cursor uapi.dst is unintentionally modified by
drm_rect_intersect.

Fix this by using local copy in clip_area_update(). Also make the damage
and the display area const.

Fixes: 1bff93b8bc27 ("drm/i915/psr: Extend SU area to cover cursor fully if needed")
Cc: <stable@vger.kernel.org> # v6.9+
Assisted-by: GitHub-Copilot:claude-opus-5
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index d8fefb13c2790..99603a486c278 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -2709,23 +2709,25 @@ static u32 psr2_pipe_srcsz_early_tpt_calc(struct intel_crtc_state *crtc_state,
 }
 
 static void clip_area_update(struct drm_rect *overlap_damage_area,
-			     struct drm_rect *damage_area,
-			     struct drm_rect *display_area)
+			     const struct drm_rect *damage_area,
+			     const struct drm_rect *display_area)
 {
-	if (!drm_rect_intersect(damage_area, display_area))
+	struct drm_rect inter = *damage_area;
+
+	if (!drm_rect_intersect(&inter, display_area))
 		return;
 
 	if (overlap_damage_area->y1 == -1) {
-		overlap_damage_area->y1 = damage_area->y1;
-		overlap_damage_area->y2 = damage_area->y2;
+		overlap_damage_area->y1 = inter.y1;
+		overlap_damage_area->y2 = inter.y2;
 		return;
 	}
 
-	if (damage_area->y1 < overlap_damage_area->y1)
-		overlap_damage_area->y1 = damage_area->y1;
+	if (inter.y1 < overlap_damage_area->y1)
+		overlap_damage_area->y1 = inter.y1;
 
-	if (damage_area->y2 > overlap_damage_area->y2)
-		overlap_damage_area->y2 = damage_area->y2;
+	if (inter.y2 > overlap_damage_area->y2)
+		overlap_damage_area->y2 = inter.y2;
 }
 
 static bool intel_psr2_sel_fetch_pipe_alignment(struct intel_crtc_state *crtc_state)
-- 
2.43.0