[igt-dev] [PATCH i-g-t v2] tests/kms_chamelium: Make sure we wait for each connectors' hotplug event

[Imre Deak]

After scheduling an HPD toggle event, make sure that we wait for the
hotplug event for each connector that may be sent by the driver.

Depending on the scheduling there could be 1 event or as many events as
connectors we scheduled an HPD toggle event on, depending on the timing.
So if we don't yet see the expected connector state on a given connector
try to wait for an additional hotplug event and reprobe/recheck the
state.

v2:
- s/igt_assert(x >= y)/igt_assert_lte(y, x)/ to see the actual limits in
  the debugging output. (Lyude)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110534
Cc: Paul Kocialkowski <paul.kocialkowski at bootlin.com>
Cc: Lyude Paul <lyude at redhat.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
Reviewed-by: Lyude Paul <lyude at redhat.com>
---
 tests/kms_chamelium.c | 45 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/tests/kms_chamelium.c b/tests/kms_chamelium.c
index 714e5e06..502f1efa 100644
--- a/tests/kms_chamelium.c
+++ b/tests/kms_chamelium.c
@@ -284,11 +284,32 @@ test_edid_read(data_t *data, struct chamelium_port *port,
 	drmModeFreeConnector(connector);
 }
 
+/* Wait for hotplug and return the remaining time left from timeout */
+static bool wait_for_hotplug(struct udev_monitor *mon, int *timeout)
+{
+	struct timespec start, end;
+	int elapsed;
+	bool detected;
+
+	igt_assert_eq(igt_gettime(&start), 0);
+	detected = igt_hotplug_detected(mon, *timeout);
+	igt_assert_eq(igt_gettime(&end), 0);
+
+	elapsed = igt_time_elapsed(&start, &end);
+	igt_assert_lte(0, elapsed);
+	*timeout = max(0, *timeout - elapsed);
+
+	return detected;
+}
+
 static void
 try_suspend_resume_hpd(data_t *data, struct chamelium_port *port,
 		       enum igt_suspend_state state, enum igt_suspend_test test,
 		       struct udev_monitor *mon, bool connected)
 {
+	drmModeConnection target_state = connected ? DRM_MODE_DISCONNECTED :
+						     DRM_MODE_CONNECTED;
+	int timeout = HOTPLUG_TIMEOUT;
 	int delay;
 	int p;
 
@@ -310,17 +331,29 @@ try_suspend_resume_hpd(data_t *data, struct chamelium_port *port,
 	}
 
 	igt_system_suspend_autoresume(state, test);
+	igt_assert(wait_for_hotplug(mon, &timeout));
 
-	igt_assert(igt_hotplug_detected(mon, HOTPLUG_TIMEOUT));
 	if (port) {
-		igt_assert_eq(reprobe_connector(data, port), connected ?
-			      DRM_MODE_DISCONNECTED : DRM_MODE_CONNECTED);
+		igt_assert_eq(reprobe_connector(data, port), target_state);
 	} else {
 		for (p = 0; p < data->port_count; p++) {
+			drmModeConnection current_state;
+
 			port = data->ports[p];
-			igt_assert_eq(reprobe_connector(data, port), connected ?
-				      DRM_MODE_DISCONNECTED :
-				      DRM_MODE_CONNECTED);
+			/*
+			 * There could be as many hotplug events sent by
+			 * driver as connectors we scheduled an HPD toggle on
+			 * above, depending on timing. So if we're not seeing
+			 * the expected connector state try to wait for an HPD
+			 * event for each connector/port.
+			 */
+			current_state = reprobe_connector(data, port);
+			if (p > 0 && current_state != target_state) {
+				igt_assert(wait_for_hotplug(mon, &timeout));
+				current_state = reprobe_connector(data, port);
+			}
+
+			igt_assert_eq(current_state, target_state);
 		}
 
 		port = NULL;
-- 
2.17.1