[PATCH i-g-t 37/39] lib/vkms: Test changing enabled device encoders

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

Test that, once a VKMS device is enabled, the encoder values can't
change and that deleting it or the attached CRTCs doesn't change the
VKMS device.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 lib/igt_vkms.c             | 12 ++++++++
 lib/igt_vkms.h             |  1 +
 tests/vkms/vkms_configfs.c | 62 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+)

diff --git a/lib/igt_vkms.c b/lib/igt_vkms.c
index 58c71ca08..95fbf5773 100644
--- a/lib/igt_vkms.c
+++ b/lib/igt_vkms.c
@@ -648,6 +648,18 @@ void igt_vkms_device_add_encoder(igt_vkms_t *dev, const char *name)
 	add_pipeline_item(dev, VKMS_PIPELINE_ITEM_ENCODER, name);
 }
 
+/**
+ * igt_vkms_device_remove_encoder:
+ * @dev: Device to remove the encoder from
+ * @name: Encoder name
+ *
+ * Remove an existing encoder from the VKMS device.
+ */
+bool igt_vkms_device_remove_encoder(igt_vkms_t *dev, const char *name)
+{
+	return remove_pipeline_item(dev, VKMS_PIPELINE_ITEM_ENCODER, name);
+}
+
 /**
  * igt_vkms_encoder_attach_crtc:
  * @dev: Target device
diff --git a/lib/igt_vkms.h b/lib/igt_vkms.h
index e1f63d809..b82282a11 100644
--- a/lib/igt_vkms.h
+++ b/lib/igt_vkms.h
@@ -88,6 +88,7 @@ void igt_vkms_crtc_set_writeback_enabled(igt_vkms_t *dev, const char *name,
 					 bool writeback);
 
 void igt_vkms_device_add_encoder(igt_vkms_t *dev, const char *name);
+bool igt_vkms_device_remove_encoder(igt_vkms_t *dev, const char *name);
 bool igt_vkms_encoder_attach_crtc(igt_vkms_t *dev, const char *encoder_name,
 				  const char *crtc_name);
 bool igt_vkms_encoder_detach_crtc(igt_vkms_t *dev, const char *encoder_name,
diff --git a/tests/vkms/vkms_configfs.c b/tests/vkms/vkms_configfs.c
index d8ae1f073..be311e77e 100644
--- a/tests/vkms/vkms_configfs.c
+++ b/tests/vkms/vkms_configfs.c
@@ -1614,6 +1614,67 @@ static void test_enabled_crtc_cannot_change(void)
 	igt_vkms_device_destroy(dev);
 }
 
+/**
+ * SUBTEST: enabled-encoder-cannot-change
+ * Description: Test that, once a VKMS device is enabled, the encoder values
+ *              can't change and that deleting it or the attached CRTCs doesn't
+ *              change the VKMS device.
+ */
+
+static void test_enabled_encoder_cannot_change(void)
+{
+	igt_vkms_t *dev;
+
+	igt_vkms_config_t cfg = {
+		.device_name = __func__,
+		.planes = {
+			{
+				.name = "plane0",
+				.type = DRM_PLANE_TYPE_PRIMARY,
+				.possible_crtcs = { "crtc0"},
+			},
+			{
+				.name = "plane1",
+				.type = DRM_PLANE_TYPE_PRIMARY,
+				.possible_crtcs = { "crtc1"},
+			},
+		},
+		.crtcs = {
+			{ .name = "crtc0" },
+			{ .name = "crtc1" },
+		},
+		.encoders = {
+			{ .name = "encoder0", .possible_crtcs = { "crtc0" } },
+			{ .name = "encoder1", .possible_crtcs = { "crtc1" } },
+		},
+		.connectors = {
+			{
+				.name = "connector0",
+				.possible_encoders = { "encoder0", "encoder1" },
+			},
+		},
+	};
+
+	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));
+	assert_device_config(&cfg);
+
+	/* Try to change values */
+	igt_assert(!igt_vkms_encoder_attach_crtc(dev, "encoder0", "crtc1"));
+
+	/* Deleting pipeline items doesn't affect the device */
+	igt_assert(igt_vkms_encoder_detach_crtc(dev, "encoder0", "crtc0"));
+	igt_assert(igt_vkms_connector_detach_encoder(dev, "connector0",
+						     "encoder0"));
+	igt_assert(igt_vkms_device_remove_encoder(dev, "encoder0"));
+	assert_device_config(&cfg);
+
+	igt_vkms_device_destroy(dev);
+}
+
 igt_main
 {
 	struct {
@@ -1653,6 +1714,7 @@ igt_main
 		{ "enable-too-many-connectors", test_enable_too_many_connectors },
 		{ "enabled-plane-cannot-change", test_enabled_plane_cannot_change },
 		{ "enabled-crtc-cannot-change", test_enabled_crtc_cannot_change },
+		{ "enabled-encoder-cannot-change", test_enabled_encoder_cannot_change },
 	};
 
 	igt_fixture {
-- 
2.48.1