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-rw-r--r--include/linux/delay.h6
-rw-r--r--kernel/timer.c22
2 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/delay.h b/include/linux/delay.h
index fd832c6d419..0e303d1aacd 100644
--- a/include/linux/delay.h
+++ b/include/linux/delay.h
@@ -45,6 +45,12 @@ 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 usleep(unsigned long usecs)
+{
+ usleep_range(usecs, usecs);
+}
static inline void ssleep(unsigned int seconds)
{
diff --git a/kernel/timer.c b/kernel/timer.c
index ce98685cd1c..f110f241ab6 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;
+ 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);