tests/kms_content_protection: Fix uevent subtest

Parameters initialized at udev_init were not passed back to
caller. Hence uevent were not captured.

v2: Using double pointer for udev_monitor and udev. [Ram]

Cc: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/344864/?series=70773&rev=2

tests/kms_content_protection.c

@@ -165,24 +165,24 @@ static void hdcp_udev_fini(struct udev_monitor *uevent_monitor,
 		udev_unref(udev);
 }
 
-static int hdcp_udev_init(struct udev_monitor *uevent_monitor,
-			  struct udev *udev)
+static int hdcp_udev_init(struct udev_monitor **uevent_monitor,
+			  struct udev **udev, int *udev_fd)
 {
 	int ret = -EINVAL;
 
-	udev = udev_new();
-	if (!udev) {
+	*udev = udev_new();
+	if (!*udev) {
 		igt_info("failed to create udev object\n");
 		goto out;
 	}
 
-	uevent_monitor = udev_monitor_new_from_netlink(udev, "udev");
-	if (!uevent_monitor) {
+	*uevent_monitor = udev_monitor_new_from_netlink(*udev, "udev");
+	if (!*uevent_monitor) {
 		igt_info("failed to create udev event monitor\n");
 		goto out;
 	}
 
-	ret = udev_monitor_filter_add_match_subsystem_devtype(uevent_monitor,
+	ret = udev_monitor_filter_add_match_subsystem_devtype(*uevent_monitor,
 							      "drm",
 							      "drm_minor");
 	if (ret < 0) {
@@ -190,16 +190,23 @@ static int hdcp_udev_init(struct udev_monitor *uevent_monitor,
 		goto out;
 	}
 
-	ret = udev_monitor_enable_receiving(uevent_monitor);
+	ret = udev_monitor_enable_receiving(*uevent_monitor);
 	if (ret < 0) {
 		igt_info("failed to enable udev event reception\n");
 		goto out;
 	}
 
-	return udev_monitor_get_fd(uevent_monitor);
+	*udev_fd = udev_monitor_get_fd(*uevent_monitor);
+	if (*udev_fd < 0) {
+		igt_info("failed to get udev_fd on uevent monitor\n");
+		ret = *udev_fd;
+		goto out;
+	}
+
+	return ret;
 
 out:
-	hdcp_udev_fini(uevent_monitor, udev);
+	hdcp_udev_fini(*uevent_monitor, *udev);
 	return ret;
 }
 
@@ -214,8 +221,7 @@ static bool wait_for_hdcp_event(uint32_t conn_id, uint32_t prop_id,
 	struct epoll_event event, events[MAX_EVENTS];
 	bool ret = false;
 
-	udev_fd = hdcp_udev_init(uevent_monitor, udev);
-	if (udev_fd < 0)
+	if (hdcp_udev_init(&uevent_monitor, &udev, &udev_fd) < 0)
 		return false;
 
 	epoll_fd = epoll_create1(0);