1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
index 1c4070ced066..c070b53984e4 100644
--- a/drivers/char/mmtimer.c
+++ b/drivers/char/mmtimer.c
@@ -32,7 +32,7 @@
 #include <linux/interrupt.h>
 #include <linux/time.h>
 #include <linux/math64.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 
 #include <asm/uaccess.h>
@@ -59,6 +59,7 @@ extern unsigned long sn_rtc_cycles_per_second;
 
 #define rtc_time()              (*RTC_COUNTER_ADDR)
 
+static DEFINE_MUTEX(mmtimer_mutex);
 static long mmtimer_ioctl(struct file *file, unsigned int cmd,
                                                 unsigned long arg);
 static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
@@ -372,7 +373,7 @@ static long mmtimer_ioctl(struct file *file, unsigned int cmd,
 {
         int ret = 0;
 
-        lock_kernel();
+        mutex_lock(&mmtimer_mutex);
 
         switch (cmd) {
         case MMTIMER_GETOFFSET: /* offset of the counter */
@@ -415,7 +416,7 @@ static long mmtimer_ioctl(struct file *file, unsigned int cmd,
                 ret = -ENOTTY;
                 break;
         }
-        unlock_kernel();
+        mutex_unlock(&mmtimer_mutex);
         return ret;
 }