[Intel-gfx] [PATCH igt] igt/kms_atomic: Match CRTC harder for special planes

[Daniel Stone]

Our heuristic for finding planes was previously matching the type, and
ensuring that the plane was valid for that CRTC. However, VC4 now has
primary/cursor planes which can wander multiple CRTCs, so we could pick
a PRIMARY plane which was not the kernel's idea of crtc->primary,
causing plane_primary_legacy to fail; ditto for cursor.

Make find_plane try harder, by preferring to return planes which are
already on the requested CRTC.

Signed-off-by: Daniel Stone <daniels at collabora.com>
Reported-by: Robert Foss <robert.foss at collabora.com>
Cc: Eric Anholt <eric at anholt.net>
---
 tests/kms_atomic.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/tests/kms_atomic.c b/tests/kms_atomic.c
index 1441fdf..e6d71c3 100644
--- a/tests/kms_atomic.c
+++ b/tests/kms_atomic.c
@@ -451,6 +451,7 @@ static struct kms_atomic_plane_state *
 find_plane(struct kms_atomic_state *state, enum plane_type type,
 	   struct kms_atomic_crtc_state *crtc)
 {
+	struct kms_atomic_plane_state *ret = NULL;
 	int i;
 
 	for (i = 0; i < state->num_planes; i++) {
@@ -464,10 +465,18 @@ find_plane(struct kms_atomic_state *state, enum plane_type type,
 			continue;
 
 		plane_get_current_state(plane);
-		return plane;
+
+		/* Try to find a plane that's already on this CRTC. In
+		 * particular, this ensures that for special (primary/cursor)
+		 * planes that can be on multiple CRTCs, we find the same
+		 * one that the legacy ioctls will. */
+		if (!crtc || plane->crtc_id == crtc->obj)
+			return plane;
+
+		ret = plane;
 	}
 
-	return NULL;
+	return ret;
 }
 
 static void crtc_populate_req(struct kms_atomic_crtc_state *crtc,
-- 
2.10.2