[PATCH 5.10 041/106] rtc: mc146818: Reduce spinlock section in mc146818_set_time()

Greg Kroah-Hartman
2022-12-12T13:14:28Z

From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit dcf257e92622ba0e25fdc4b6699683e7ae67e2a1 ]

No need to hold the lock and disable interrupts for doing math.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.709243630@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/rtc/rtc-mc146818-lib.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c
index 46527a5d3912..1ca866461d10 100644
--- a/drivers/rtc/rtc-mc146818-lib.c
+++ b/drivers/rtc/rtc-mc146818-lib.c
@@ -249,7 +249,6 @@ int mc146818_set_time(struct rtc_time *time)
if (yrs > 255) /* They are unsigned */
return -EINVAL;

- spin_lock_irqsave(&rtc_lock, flags);
#ifdef CONFIG_MACH_DECSTATION
real_yrs = yrs;
leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||
@@ -278,10 +277,8 @@ int mc146818_set_time(struct rtc_time *time)
/* These limits and adjustments are independent of
* whether the chip is in binary mode or not.
*/
- if (yrs > 169) {
- spin_unlock_irqrestore(&rtc_lock, flags);
+ if (yrs > 169)
return -EINVAL;
- }

if (yrs >= 100)
yrs -= 100;
@@ -297,6 +294,7 @@ int mc146818_set_time(struct rtc_time *time)
century = bin2bcd(century);
}

+ spin_lock_irqsave(&rtc_lock, flags);
save_control = CMOS_READ(RTC_CONTROL);
CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
--
2.35.1