serial: nuttx: revert tcdrain back to fsync (#25538)

* serial: nuttx: revert tcdrain back to fsync * serial: do not print error on EAGAIN --------- Co-authored-by: Alexander Lerach <alexander@auterion.com>
2026-05-21 04:33:10 +08:00 · 2025-09-11 12:32:34 -08:00
parent 7b68c5dbfc
commit 1aad8b6ec9
3 changed files with 13 additions and 7 deletions
@@ -355,12 +355,15 @@ ssize_t SerialImpl::write(const void *buffer, size_t buffer_size)
 	}

 	int written = ::write(_serial_fd, buffer, buffer_size);
-	tcdrain(_serial_fd); // Wait until all output is transmitted

 	if (written < 0) {
-		PX4_ERR("%s write error %d", _port, written);
+		if (errno != EAGAIN) {
+			PX4_ERR("%s write error %d", _port, written);
+		}
 	}

+	::fsync(_serial_fd);
+
 	return written;
 }

@@ -337,13 +337,15 @@ ssize_t SerialImpl::write(const void *buffer, size_t buffer_size)
 	}

 	int written = ::write(_serial_fd, buffer, buffer_size);
-	::fsync(_serial_fd);

 	if (written < 0) {
-		PX4_ERR("%s write error %d", _port, written);
-
+		if (errno != EAGAIN) {
+			PX4_ERR("%s write error %d", _port, written);
+		}
 	}

+	::fsync(_serial_fd);
+
 	return written;
 }

@@ -268,8 +268,9 @@ ssize_t SerialImpl::write(const void *buffer, size_t buffer_size)
 	int ret_write = qurt_uart_write(_serial_fd, (const char *) buffer, buffer_size);

 	if (ret_write < 0) {
-		PX4_ERR("%s write error %d", _port, ret_write);
-
+		if (errno != EAGAIN) {
+			PX4_ERR("%s write error %d", _port, ret_write);
+		}
 	}

 	return ret_write;