rtc: ds3232: fix read on /dev/rtc after RTC_AIE_ON (dfc2532b) · Commits · 戴 / test

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:

Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by:

Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-ds3232.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -272,7 +272,7 @@ out:
		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;
		}

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