[PATCH i-g-t 22/39] tests/vkms_configfs: Test adding too many planes

["José Expósito" <jose.exposito89@gmail.com>]

The kernel references pipeline items with 32 bit bitmaks, therefore,
adding more than 31 items causes an overflow.

Make sure that this limit is handled correctly.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 tests/vkms/vkms_configfs.c | 53 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/tests/vkms/vkms_configfs.c b/tests/vkms/vkms_configfs.c
index 47cfa475f..7df9bda01 100644
--- a/tests/vkms/vkms_configfs.c
+++ b/tests/vkms/vkms_configfs.c
@@ -787,6 +787,58 @@ static void test_enable_no_planes(void)
 	igt_vkms_device_destroy(dev);
 }
 
+/**
+ * SUBTEST: enable-too-many-planes
+ * Description: Try to enable a VKMS device with too many planes and test that
+ *              it fails.
+ */
+
+static void test_enable_too_many_planes(void)
+{
+	igt_vkms_t *dev;
+	char plane_names[VKMS_MAX_PIPELINE_ITEMS][8];
+
+	igt_vkms_config_t cfg = {
+		.device_name = __func__,
+		.planes = {
+			{
+				.name = "plane0",
+				.type = DRM_PLANE_TYPE_PRIMARY,
+				.possible_crtcs = { "crtc0" },
+			},
+		},
+		.crtcs = {
+			{ .name = "crtc0" },
+		},
+		.encoders = {
+			{ .name = "encoder0", .possible_crtcs = { "crtc0" } },
+		},
+		.connectors = {
+			{
+				.name = "connector0",
+				.possible_encoders = { "encoder0" },
+			},
+		},
+	};
+
+	for (int n = 1; n < 32; n++) {
+		snprintf(plane_names[n], sizeof(plane_names[n]), "plane%d", n);
+		cfg.planes[n] = (igt_vkms_plane_config_t){
+			.name = plane_names[n],
+			.possible_crtcs = { "crtc0" },
+		};
+	}
+
+	dev = igt_vkms_device_create_from_config(&cfg);
+	igt_assert(dev);
+
+	igt_vkms_device_set_enabled(dev, true);
+	igt_assert(!igt_vkms_device_is_enabled(dev));
+	igt_assert(!device_exists(__func__));
+
+	igt_vkms_device_destroy(dev);
+}
+
 igt_main
 {
 	struct {
@@ -811,6 +863,7 @@ igt_main
 		{ "attach-connector-to-encoder", test_attach_connector_to_encoder },
 		{ "enable-no-pipeline-items", test_enable_no_pipeline_items },
 		{ "enable-no-planes", test_enable_no_planes },
+		{ "enable-too-many-planes", test_enable_too_many_planes },
 	};
 
 	igt_fixture {
-- 
2.48.1