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rtc: r7301: Fix a possible sleep-in-atomic bug in rtc7301_read_time 

The driver may sleep under a spinlock.
The function call path is:
rtc7301_read_time (acquire the spinlock)
  rtc7301_wait_while_busy
    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>
This commit is contained in:
Jia-Ju Bai 2017-12-13 21:55:50 +08:00 committed by Alexandre Belloni
parent 2da6877f0e
commit cd8c0bb2bd
1 changed files with 1 additions and 1 deletions
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2
drivers/rtc/rtc-r7301.c
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@ -95,7 +95,7 @@ static int rtc7301_wait_while_busy(struct rtc7301_priv *priv)
if (!(val & RTC7301_CONTROL_BUSY)) if (!(val & RTC7301_CONTROL_BUSY))
return 0; return 0;
usleep_range(200, 300); udelay(300);
} }
return -ETIMEDOUT; return -ETIMEDOUT;