[PATCH i-g-t v2 13/43] lib/vkms: Test CRTC invalid values

[José Expósito]

For a VKMS CRTC, it is only possible to set invalid values in the
writeback connector status.

Test that setting wrong values fails and that the CRTC status is not
accidentally changed.

Reviewed-by: Louis Chauvet <louis.chauvet at bootlin.com>
Signed-off-by: José Expósito <jose.exposito89 at gmail.com>
---
 lib/igt_vkms.c             | 18 ++++++++++++++++++
 lib/igt_vkms.h             |  2 ++
 tests/vkms/vkms_configfs.c | 26 ++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/lib/igt_vkms.c b/lib/igt_vkms.c
index 0c3c9812a..0a14f9af7 100644
--- a/lib/igt_vkms.c
+++ b/lib/igt_vkms.c
@@ -509,3 +509,21 @@ bool igt_vkms_crtc_is_writeback_enabled(igt_vkms_t *dev, const char *name)
 
 	return read_bool(path);
 }
+
+/**
+ * igt_vkms_crtc_set_writeback_enabled:
+ * @dev: Device the CRTC belongs to
+ * @name: CRTC name
+ * @writeback: Enable or disable the writeback connector
+ *
+ * Set the VKMS CRTC writeback connector is status.
+ */
+void igt_vkms_crtc_set_writeback_enabled(igt_vkms_t *dev, const char *name,
+					 bool writeback)
+{
+	char path[PATH_MAX];
+
+	igt_vkms_get_crtc_writeback_path(dev, name, path, sizeof(path));
+
+	write_bool(path, writeback);
+}
diff --git a/lib/igt_vkms.h b/lib/igt_vkms.h
index 23c0560f8..90cfde77a 100644
--- a/lib/igt_vkms.h
+++ b/lib/igt_vkms.h
@@ -45,5 +45,7 @@ void igt_vkms_plane_set_type(igt_vkms_t *dev, const char *name, int type);
 
 void igt_vkms_device_add_crtc(igt_vkms_t *dev, const char *name);
 bool igt_vkms_crtc_is_writeback_enabled(igt_vkms_t *dev, const char *name);
+void igt_vkms_crtc_set_writeback_enabled(igt_vkms_t *dev, const char *name,
+					 bool writeback);
 
 #endif /* __IGT_VKMS_H__ */
diff --git a/tests/vkms/vkms_configfs.c b/tests/vkms/vkms_configfs.c
index 7f0e07121..1d96a627c 100644
--- a/tests/vkms/vkms_configfs.c
+++ b/tests/vkms/vkms_configfs.c
@@ -357,6 +357,31 @@ static void test_crtc_default_values(void)
 	igt_vkms_device_destroy(dev);
 }
 
+/**
+ * SUBTEST: crtc-wrong-values
+ * Description: Check that setting unexpected values doesn't work.
+ */
+
+static void test_crtc_wrong_values(void)
+{
+	igt_vkms_t *dev;
+	char path[PATH_MAX];
+
+	/* Test invalid values for "writeback" */
+	dev = igt_vkms_device_create(__func__);
+	igt_assert(dev);
+
+	igt_vkms_device_add_crtc(dev, "crtc0");
+	igt_vkms_crtc_set_writeback_enabled(dev, "crtc0", true);
+	igt_assert(igt_vkms_crtc_is_writeback_enabled(dev, "crtc0"));
+	igt_vkms_get_crtc_writeback_path(dev, "crtc0", path, sizeof(path));
+
+	assert_wrong_bool_values(path);
+	igt_assert(igt_vkms_crtc_is_writeback_enabled(dev, "crtc0"));
+
+	igt_vkms_device_destroy(dev);
+}
+
 igt_main
 {
 	struct {
@@ -372,6 +397,7 @@ igt_main
 		{ "plane-valid-values", test_plane_valid_values },
 		{ "crtc-default-files", test_crtc_default_files },
 		{ "crtc-default-values", test_crtc_default_values },
+		{ "crtc-wrong-values", test_crtc_wrong_values },
 	};
 
 	igt_fixture {
-- 
2.48.1