[PATCH] auxdisplay: charlcd: delete mdelay in long_sleep

From: Jia-Ju Bai
Date: Fri Jan 26 2018 - 10:14:48 EST


The function long_sleep() calls mdelay() when in an interrupt handler.
But only charlcd_clear_display() and charlcd_init_display calls
long_sleep(), and my tool finds that the two functions
are never called in an interrupt handler.
Thus mdelay() and in_interrupt() are not necessary.

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/auxdisplay/charlcd.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 642afd8..9e84795 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -102,10 +102,7 @@ struct charlcd_priv {
/* sleeps that many milliseconds with a reschedule */
static void long_sleep(int ms)
{
- if (in_interrupt())
- mdelay(ms);
- else
- schedule_timeout_interruptible(msecs_to_jiffies(ms));
+ schedule_timeout_interruptible(msecs_to_jiffies(ms));
}

/* turn the backlight on or off */
--
1.7.9.5