[tip: timers/core] rtc: mc146818: Reduce spinlock section in mc146818_set_time()

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     dcf257e92622ba0e25fdc4b6699683e7ae67e2a1
Gitweb:        https://git.kernel.org/tip/dcf257e92622ba0e25fdc4b6699683e7ae67e2a1
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Sun, 06 Dec 2020 22:46:15 +01:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 11 Dec 2020 10:40:52 +01:00

rtc: mc146818: Reduce spinlock section in mc146818_set_time()

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

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20201206220541.709243630@xxxxxxxxxxxxx

---
 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 98048bb..972a5b9 100644
--- a/drivers/rtc/rtc-mc146818-lib.c
+++ b/drivers/rtc/rtc-mc146818-lib.c
@@ -135,7 +135,6 @@ 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)) ||
@@ -164,10 +163,8 @@ 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;
@@ -183,6 +180,7 @@ 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);