rtc: r7301: Fix a possible sleep-in-atomic bug in rtc7301_set_time

The driver may sleep under a spinlock.
The function call path is:
rtc7301_set_time (acquire the spinlock)
  usleep_range --> may sleep

To fix it, usleep_range is replaced with udelay.

This bug is found by my static analysis tool(DSAC) and checked by my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c
index d846e97..500e8c8 100644 (file)
--- a/drivers/rtc/rtc-r7301.c
+++ b/drivers/rtc/rtc-r7301.c
@@ -235,7 +235,7 @@ static int rtc7301_set_time(struct device *dev, struct rtc_time *tm)
        spin_lock_irqsave(&priv->lock, flags);
 
        rtc7301_stop(priv);
-       usleep_range(200, 300);
+       udelay(300);
        rtc7301_select_bank(priv, 0);
        rtc7301_write_time(priv, tm, false);
        rtc7301_start(priv);