[igt-dev] [PATCH i-g-t 3/3] tests/kms_chamelium: add a link-status test

[Simon Ser]

This test first checks that on normal hotplug, the link-status property is set
to GOOD. It then triggers a link failure, checks that the property is updated
to BAD. Checks are performed to make sure the new mode list is a subset of the
previous one. After that, a new modeset is performed if necessary and the
link-status property is set back to GOOD.

This whole dance is repeated until we reach fallback modes.

Signed-off-by: Simon Ser <simon.ser at intel.com>
---
 tests/kms_chamelium.c | 142 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)

diff --git a/tests/kms_chamelium.c b/tests/kms_chamelium.c
index b7d30a2d0f55..bef4d6d3bbd8 100644
--- a/tests/kms_chamelium.c
+++ b/tests/kms_chamelium.c
@@ -539,6 +539,145 @@ enable_output(data_t *data,
 	drmModeFreeConnector(connector);
 }
 
+static bool find_mode(const drmModeModeInfo *list, size_t list_len,
+		      const drmModeModeInfo *mode)
+{
+	size_t i;
+
+	for (i = 0; i < list_len; i++) {
+		if (memcmp(&list[i], mode, sizeof(*mode)) == 0) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+static void check_modes_subset(const drmModeModeInfo *prev, size_t prev_len,
+			       const drmModeModeInfo *cur, size_t cur_len)
+{
+	size_t i;
+
+	for (i = 0; i < cur_len; i++) {
+		igt_assert_f(find_mode(prev, prev_len, &cur[i]),
+			     "Got new mode %s after link status failure\n",
+			     cur[i].name);
+	}
+
+	igt_assert(cur_len <= prev_len); /* safety net */
+	igt_debug("New mode list contains %zu less modes\n",
+		  prev_len - cur_len);
+}
+
+static bool are_fallback_modes(const drmModeModeInfo *modes, size_t modes_len)
+{
+	igt_assert(modes_len > 0);
+
+	return modes[0].hdisplay <= 1024 && modes[0].vdisplay <= 768;
+}
+
+static void
+test_link_status(data_t *data, struct chamelium_port *port)
+{
+	drmModeConnector *connector;
+	igt_output_t *output;
+	igt_plane_t *primary;
+	drmModeModeInfo *prev_modes;
+	size_t prev_modes_len;
+	drmModeModeInfo mode = {0};
+	uint32_t link_status_id;
+	uint64_t link_status;
+	bool has_prop;
+	unsigned int fb_id = 0;
+	struct igt_fb fb;
+	struct udev_monitor *mon;
+
+	igt_require(chamelium_supports_trigger_link_failure(data->chamelium));
+
+	reset_state(data, port);
+
+	output = prepare_output(data, port, TEST_EDID_BASE);
+	connector = chamelium_port_get_connector(data->chamelium, port, false);
+	primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
+	igt_assert(primary);
+
+	has_prop = kmstest_get_property(data->drm_fd, connector->connector_id,
+					DRM_MODE_OBJECT_CONNECTOR,
+					"link-status", &link_status_id,
+					&link_status, NULL);
+	igt_require(has_prop);
+	igt_assert_f(link_status == DRM_MODE_LINK_STATUS_GOOD,
+		     "Expected link status to be %d initially, got %"PRIu64"\n",
+		     DRM_MODE_LINK_STATUS_GOOD, link_status);
+
+	igt_debug("Connector has %d modes\n", connector->count_modes);
+	prev_modes_len = connector->count_modes;
+	prev_modes = malloc(prev_modes_len * sizeof(drmModeModeInfo));
+	memcpy(prev_modes, connector->modes,
+	       prev_modes_len * sizeof(drmModeModeInfo));
+
+	mon = igt_watch_hotplug();
+
+	while (1) {
+		if (link_status == DRM_MODE_LINK_STATUS_BAD) {
+			igt_output_set_prop_value(output,
+						  IGT_CONNECTOR_LINK_STATUS,
+						  DRM_MODE_LINK_STATUS_GOOD);
+		}
+
+		if (memcmp(&connector->modes[0], &mode, sizeof(mode)) != 0) {
+			igt_assert(connector->count_modes > 0);
+			mode = connector->modes[0];
+			igt_debug("Modesetting with %s\n", mode.name);
+			if (fb_id > 0)
+				igt_remove_fb(data->drm_fd, &fb);
+			fb_id = igt_create_color_pattern_fb(data->drm_fd,
+							    mode.hdisplay,
+							    mode.vdisplay,
+							    DRM_FORMAT_XRGB8888,
+							    LOCAL_DRM_FORMAT_MOD_NONE,
+							    0, 0, 0, &fb);
+			igt_assert(fb_id > 0);
+			enable_output(data, port, output, &mode, &fb);
+		} else {
+			igt_display_commit2(&data->display, COMMIT_ATOMIC);
+		}
+
+		igt_debug("Triggering link failure\n");
+		chamelium_trigger_link_failure(data->chamelium, port);
+
+		igt_assert(igt_hotplug_detected(mon, HOTPLUG_TIMEOUT));
+		igt_assert_eq(reprobe_connector(data, port),
+			      DRM_MODE_CONNECTED);
+
+		igt_flush_hotplugs(mon);
+
+		drmModeFreeConnector(connector);
+		connector = chamelium_port_get_connector(data->chamelium, port,
+							 false);
+		link_status = igt_output_get_prop(output, IGT_CONNECTOR_LINK_STATUS);
+		igt_assert_f(link_status == DRM_MODE_LINK_STATUS_BAD,
+			     "Expected link status to be %d after link failure, "
+			     "got %"PRIu64"\n",
+			     DRM_MODE_LINK_STATUS_BAD, link_status);
+		check_modes_subset(prev_modes, prev_modes_len,
+				   connector->modes, connector->count_modes);
+		prev_modes_len = connector->count_modes;
+		memcpy(prev_modes, connector->modes,
+		       connector->count_modes * sizeof(drmModeModeInfo));
+
+		if (are_fallback_modes(connector->modes, connector->count_modes)) {
+			igt_debug("Reached fallback modes\n");
+			break;
+		}
+	}
+
+	igt_cleanup_hotplug(mon);
+	igt_remove_fb(data->drm_fd, &fb);
+	free(prev_modes);
+	drmModeFreeConnector(connector);
+}
+
 static void chamelium_paint_xr24_pattern(uint32_t *data,
 					 size_t width, size_t height,
 					 size_t stride, size_t block_size)
@@ -2234,6 +2373,9 @@ igt_main
 			test_hpd_storm_disable(&data, port,
 					       HPD_STORM_PULSE_INTERVAL_DP);
 
+		connector_subtest("dp-link-status", DisplayPort)
+			test_link_status(&data, port);
+
 		connector_subtest("dp-edid-change-during-suspend", DisplayPort)
 			test_suspend_resume_edid_change(&data, port,
 							SUSPEND_STATE_MEM,
-- 
2.22.0