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Commit dfc2532b authored by Akinobu Mita's avatar Akinobu Mita Committed by Alexandre Belloni
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rtc: ds3232: fix read on /dev/rtc after RTC_AIE_ON 



The rtctest (tools/testing/selftests/timers/rtctest.c) found that
reading ds3232 rtc device immediately return the value 0x20 (RTC_AF)
without waiting alarm interrupt.

This is because alarm_irq_enable() of ds3232 driver changes RTC_AF
flag in rtc->irq_data.  So calling ioctl with RTC_AIE_ON generates
invalid value in rtc device.

The lower-level driver should not touch rtc->irq_data directly.

Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent 080481f5

drivers/rtc/rtc-ds3232.c

+3 −7
Original line number Diff line number Diff line
@@ -272,7 +272,7 @@ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
	return ret;

}



static void ds3232_update_alarm(struct device *dev)

static void ds3232_update_alarm(struct device *dev, unsigned int enabled)

{

	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	int control;
@@ -302,7 +302,7 @@ static void ds3232_update_alarm(struct device *dev) 
	if (ret)

		goto unlock;



	if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF))

	if (enabled || (ds3232->rtc->irq_data & RTC_UF))

		/* enable alarm1 interrupt */

		control |= DS3232_REG_CR_A1IE;

	else
@@ -321,12 +321,8 @@ static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) 
	if (ds3232->irq <= 0)

		return -EINVAL;



	if (enabled)

		ds3232->rtc->irq_data |= RTC_AF;

	else

		ds3232->rtc->irq_data &= ~RTC_AF;

	ds3232_update_alarm(dev, enabled);



	ds3232_update_alarm(dev);

	return 0;

}