[igt-dev] [PATCH] tests/i915/i915_pm_rpm: skip i2c subtest on VGA subconnector

[Oleg Vasilev]

The subtest compares EDID obtained through I2C with the one thorugh DRM
interface. Getting EDID through I2C on VGA is not reliable, and the test
should be skipped. However, on some machines VGA connector is
implemented as DP branch device. More background in an fdo bug [1].

The patch enables skips of the test based on a subconnector property,
introduced in the kernel series [2].

[1]: https://bugs.freedesktop.org/show_bug.cgi?id=104097
[2]: https://patchwork.freedesktop.org/series/65800/

CC: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
CC: Simon Ser <simon.ser at intel.com>
Signed-off-by: Oleg Vasilev <oleg.vasilev at intel.com>
---
 tests/i915/i915_pm_rpm.c | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/tests/i915/i915_pm_rpm.c b/tests/i915/i915_pm_rpm.c
index 2168ff72..5c512597 100644
--- a/tests/i915/i915_pm_rpm.c
+++ b/tests/i915/i915_pm_rpm.c
@@ -389,6 +389,41 @@ static drmModePropertyBlobPtr get_connector_edid(drmModeConnectorPtr connector,
 	return blob;
 }
 
+static bool is_vga(drmModeConnectorPtr connector)
+{
+	bool found;
+	uint64_t prop_value;
+	drmModePropertyPtr prop;
+	char *enum_name = NULL;
+	bool is_subconnector_vga = false;
+
+	if (connector->connector_type == DRM_MODE_CONNECTOR_VGA)
+		return true;
+
+	if (connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort)
+		return false;
+
+	found = kmstest_get_property(drm_fd, connector->connector_id,
+				     DRM_MODE_OBJECT_CONNECTOR, "subconnector",
+				     NULL, &prop_value, &prop);
+
+	igt_assert(found);
+	igt_assert(prop->flags & DRM_MODE_PROP_ENUM);
+
+	for (int i = 0; i < prop->count_enums; i++) {
+		if (prop->enums[i].value == prop_value) {
+			enum_name = prop->enums[i].name;
+			break;
+		}
+	}
+	igt_assert(enum_name);
+
+	is_subconnector_vga = (strcmp(enum_name, "VGA") == 0);
+	if (is_subconnector_vga)
+		igt_debug("This DP is in fact VGA, skipping\n");
+	return is_subconnector_vga;
+}
+
 static void init_mode_set_data(struct mode_set_data *data)
 {
 	data->res = drmModeGetResources(drm_fd);
@@ -679,7 +714,6 @@ static void test_i2c(struct mode_set_data *data)
 
 		bool got_i2c_edid = i2c_read_edid(connector_name, i2c_edid);
 		bool got_drm_edid = drm_edid != NULL;
-		bool is_vga = data->connectors[i]->connector_type == DRM_MODE_CONNECTOR_VGA;
 
 		bool edids_equal;
 
@@ -688,7 +722,7 @@ static void test_i2c(struct mode_set_data *data)
 		 * the EDID reading mostly FFs and then disabling bit-banging. Since we
 		 * don't want to reimplement everything the Kernel does, let's just
 		 * accept the fact that some VGA outputs won't be properly detected. */
-		if (is_vga)
+		if (is_vga(data->connectors[i]))
 			continue;
 
 		if (!got_i2c_edid && !got_drm_edid)
-- 
2.23.0