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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: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Akinobu Mita 2016-03-07 00:27:49 +09:00 committed by Alexandre Belloni
parent 080481f54e
commit dfc2532b55
1 changed files with 3 additions and 7 deletions
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10
drivers/rtc/rtc-ds3232.c
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@ -272,7 +272,7 @@ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
return ret; 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); struct ds3232 *ds3232 = dev_get_drvdata(dev);
int control; int control;
@ -302,7 +302,7 @@ static void ds3232_update_alarm(struct device *dev)
if (ret) if (ret)
goto unlock; goto unlock;
if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF)) if (enabled || (ds3232->rtc->irq_data & RTC_UF))
/* enable alarm1 interrupt */ /* enable alarm1 interrupt */
control |= DS3232_REG_CR_A1IE; control |= DS3232_REG_CR_A1IE;
else else
@ -321,12 +321,8 @@ static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
if (ds3232->irq <= 0) if (ds3232->irq <= 0)
return -EINVAL; return -EINVAL;
if (enabled) ds3232_update_alarm(dev, enabled);
ds3232->rtc->irq_data |= RTC_AF;
else
ds3232->rtc->irq_data &= ~RTC_AF;
ds3232_update_alarm(dev);
return 0; return 0;
} }