[igt-dev] [PATCH i-g-t v2] tests/kms_atomic: skip mutable zpos test on non-mutable planes

[Melissa Wen <mwen@igalia.com>]

plane-primary-overlay-mutable-zpos only works if both plane types have
mutable zpos property. However, drivers usually set primary zpos as
immutable and the test case just fails. Create a helper to check if a
plane have mutable zpos and skip the test case if zpos changes are not
allowed.

v1: https://patchwork.freedesktop.org/patch/554257

v2:
- document the new public function (Kamil)
- improve commit message (Kamil)
- rebase on master and replace has_zpos() by has_mutable_zpos()

Signed-off-by: Melissa Wen <mwen@igalia.com>
---
 lib/igt_kms.c      | 28 ++++++++++++++++++++++++++++
 lib/igt_kms.h      |  2 ++
 tests/kms_atomic.c |  8 ++++----
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 28105a9ef..e4dea1a60 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -3970,6 +3970,34 @@ void igt_plane_set_prop_enum(igt_plane_t *plane,
 	igt_assert(igt_plane_try_prop_enum(plane, prop, val));
 }
 
+/**
+ * igt_plane_check_prop_is_mutable:
+ * @plane: Target plane.
+ * @prop: Property to check.
+ *
+ * Check if a plane supports a given property and if this property is mutable.
+ *
+ * Returns true if the plane has the mutable property. False if the property is
+ * not support or it's immutable.
+ */
+bool igt_plane_check_prop_is_mutable(igt_plane_t *plane,
+				     enum igt_atomic_plane_properties igt_prop)
+{
+	drmModePropertyPtr prop;
+	uint64_t value;
+	bool has_prop;
+
+	has_prop = kmstest_get_property(plane->pipe->display->drm_fd,
+					plane->drm_plane->plane_id,
+					DRM_MODE_OBJECT_PLANE,
+				        igt_plane_prop_names[igt_prop], NULL,
+					&value, &prop);
+	if (!has_prop)
+		return false;
+
+	return !(prop->flags & DRM_MODE_PROP_IMMUTABLE);
+}
+
 /**
  * igt_plane_replace_prop_blob:
  * @plane: plane to set property on.
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index 8e7801a78..b3882808b 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -812,6 +812,8 @@ extern void igt_plane_replace_prop_blob(igt_plane_t *plane,
 					enum igt_atomic_plane_properties prop,
 					const void *ptr, size_t length);
 
+extern bool igt_plane_check_prop_is_mutable(igt_plane_t *plane,
+					    enum igt_atomic_plane_properties igt_prop);
 /**
  * igt_output_has_prop:
  * @output: Output to check.
diff --git a/tests/kms_atomic.c b/tests/kms_atomic.c
index aa3af936a..96cd58571 100644
--- a/tests/kms_atomic.c
+++ b/tests/kms_atomic.c
@@ -1354,10 +1354,10 @@ static void atomic_clear(data_t *data, enum pipe pipe, igt_output_t *output)
 	igt_remove_fb(data->drm_fd, &data->fb);
 }
 
-/* Returns true if plane supports zpos property. */
-static bool has_zpos(igt_plane_t *plane)
+/* Returns true if plane supports zpos property and it's mutable. */
+static bool has_mutable_zpos(igt_plane_t *plane)
 {
-	return igt_plane_has_prop(plane, IGT_PLANE_ZPOS);
+	return igt_plane_check_prop_is_mutable(plane, IGT_PLANE_ZPOS);
 }
 
 static bool
@@ -1457,7 +1457,7 @@ igt_main_args("e", NULL, help_str, opt_handler, NULL)
 			atomic_setup(&data, pipe, output);
 			if (!overlay)
 				continue;
-			if (!has_zpos(data.primary) || !has_zpos(overlay))
+			if (!has_mutable_zpos(data.primary) || !has_mutable_zpos(overlay))
 				continue;
 			if (!igt_plane_has_format_mod(data.primary, DRM_FORMAT_ARGB8888, 0x0) ||
 			    !igt_plane_has_format_mod(overlay, DRM_FORMAT_ARGB1555, 0x0))
-- 
2.42.0