fix: added minor mqtt conntion handling

If the connection is closed by the cloud, the device
will try to reconnect 2 times by default. If this is not
successful the device will reboot. The number of retries
is configurable via the CONFIG_CLOUD_RECONNECT_RETRIES
option.

Signed-off-by: Simen S. Røstad <simen.rostad@nordicsemi.no>

Kconfig

@@ -71,6 +71,10 @@ config CLOUD_POLL_PRIORITY
 	int
 	default 7
 
+config CLOUD_RECONNECT_RETRIES
+	int "Number of retires after a cloud socket POLLUP"
+	default 2
+
 endmenu # Cloud socket poll
 
 menu "Cloud codec"

src/main.c

@@ -63,6 +63,7 @@ static struct cloud_backend *cloud_backend;
 
 static bool queued_entries;
 static bool cloud_connected;
+static int cloud_connect_retries;
 
 static int head_cir_buf;
 static int num_queued_entries;
@@ -619,6 +620,7 @@ void cloud_event_handler(const struct cloud_backend *const backend,
 	case CLOUD_EVT_CONNECTED:
 		LOG_INF("CLOUD_EVT_CONNECTED");
 		cloud_connected = true;
+		cloud_connect_retries = 0;
 		cloud_synch();
 		boot_write_img_confirmed();
 		k_delayed_work_submit(&mov_timeout_work,
@@ -718,14 +720,23 @@ void cloud_poll(void)
 		if ((fds[0].revents & POLLNVAL) == POLLNVAL) {
 			LOG_ERR("Socket error: POLLNVAL");
 			LOG_ERR("The cloud socket was unexpectedly closed.");
-			break;
+			error_handler(-EIO);
+			return;
 		}
 
 		if ((fds[0].revents & POLLHUP) == POLLHUP) {
 			LOG_ERR("Socket error: POLLHUP");
 			LOG_ERR("Connection was closed by the cloud.");
+			LOG_ERR("TRYING TO RECONNECT...");
+			if (cloud_connect_retries >
+			    CONFIG_CLOUD_RECONNECT_RETRIES) {
+				LOG_ERR("Too many retires, reboot");
 			error_handler(-EIO);
-			return;
+			}
+			cloud_connect_retries++;
+			LOG_ERR("cloud connect retries %d",
+			        cloud_connect_retries);
+			break;
 		}
 
 		if ((fds[0].revents & POLLERR) == POLLERR) {