[PATCH v3 2/4] rtc: pcf85063: do not clear AIE in the interrupt handler

["A. Sverdlin" <alexander.sverdlin@siemens.com>]

From: Alexander Sverdlin <alexander.sverdlin@siemens.com>

The interrupt handler cleared the alarm interrupt enable (AIE) bit while
acknowledging the alarm flag (AF). This races with process-context updates
of AIE in pcf85063_rtc_alarm_irq_enable() and pcf85063_rtc_set_alarm():
a handler running concurrently can clobber an AIE change.

The RTC core already disables the alarm interrupt after a one-shot alarm
via the .alarm_irq_enable callback, so the handler does not need to touch
AIE at all. Acknowledge AF only and leave AIE management to the core.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
---
Changelog:
v3:
- new patch (pre-existing issue found by Sashiko)

 drivers/rtc/rtc-pcf85063.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index ac9ab1c376c0b..af900fe8ae15e 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -238,8 +238,7 @@ static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id)
 	if (val & PCF85063_CTRL2_AF) {
 		rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF);
 		regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
-				   PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
-				   0);
+				   PCF85063_CTRL2_AF, 0);
 		return IRQ_HANDLED;
 	}
 
-- 
2.55.0