2 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/delay.h b/include/linux/delay.h
index fd832c6d419e..a6ecb34cf547 100644
--- a/include/linux/delay.h
+++ b/include/linux/delay.h
@@ -45,6 +45,7 @@ extern unsigned long lpj_fine;
 void calibrate_delay(void);
 void msleep(unsigned int msecs);
 unsigned long msleep_interruptible(unsigned int msecs);
+void usleep_range(unsigned long min, unsigned long max);
 
 static inline void ssleep(unsigned int seconds)
 {
diff --git a/kernel/timer.c b/kernel/timer.c
index ce98685cd1cb..723a62e86dcb 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1755,3 +1755,25 @@ unsigned long msleep_interruptible(unsigned int msecs)
 }
 
 EXPORT_SYMBOL(msleep_interruptible);
+
+static int __sched do_usleep_range(unsigned long min, unsigned long max)
+{
+        ktime_t kmin;
+        unsigned long delta;
+
+        kmin = ktime_set(0, min * NSEC_PER_USEC);
+        delta = (max - min) * NSEC_PER_USEC;
+        return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
+}
+
+/**
+ * usleep_range - Drop in replacement for udelay where wakeup is flexible
+ * @min: Minimum time in usecs to sleep
+ * @max: Maximum time in usecs to sleep
+ */
+void usleep_range(unsigned long min, unsigned long max)
+{
+        __set_current_state(TASK_UNINTERRUPTIBLE);
+        do_usleep_range(min, max);
+}
+EXPORT_SYMBOL(usleep_range);