1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index a8187c3c8a7b..ec351005bf9d 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -136,6 +136,7 @@
 #include <linux/spinlock.h>
 #include <linux/sched.h>
 #include <linux/tty.h>
+#include <linux/mutex.h>
 
 struct uart_port;
 struct uart_info;
@@ -284,7 +285,7 @@ struct uart_state {
         struct uart_info        *info;
         struct uart_port        *port;
 
-        struct semaphore        sem;
+        struct mutex            mutex;
 };
 
 #define UART_XMIT_SIZE  PAGE_SIZE