diff --git a/mbtk/mbtk_gnssd/gnss_main.c b/mbtk/mbtk_gnssd/gnss_main.c
index 8b91df2..a495f4f 100755
--- a/mbtk/mbtk_gnssd/gnss_main.c
+++ b/mbtk/mbtk_gnssd/gnss_main.c
@@ -322,6 +322,15 @@
 
     if(gnss_usb_nmea_port_fd > 0) {
         ret = write(gnss_usb_nmea_port_fd, nmea, nmea_len);
+        if(ret < 0 && errno != EAGAIN) {
+            LOGE("gnss_port_fd write fail [errno = %d].", errno);
+            if(errno == EIO) {
+                tcflush(gnss_usb_nmea_port_fd, TCIOFLUSH);
+                close(gnss_usb_nmea_port_fd);
+                gnss_usb_nmea_port_fd = -1;
+                gnss_usb_nmea_port_fd = gnss_port_open(GNSS_PORT_USB_NMEA, O_RDWR | O_NONBLOCK | O_NOCTTY, 115200, TRUE);
+            }
+        }
     }
 
     if(gnss_uart_at_port_fd > 0) {