[rtc-linux] [PATCH v4 3/7] rtc: ds3232: fix read on /dev/rtc after RTC_AIE_ON
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: 2016-03-06 15:28:18
Subsystem:
real time clock (rtc) subsystem, the rest · Maintainers:
Alexandre Belloni, Linus Torvalds
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> Cc: Alessandro Zummo <redacted> Cc: Alexandre Belloni <redacted> Cc: Dennis Aberilla <redacted> --- * No changes from the previous version drivers/rtc/rtc-ds3232.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index 81aa104..b27acea 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c@@ -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; }
--
2.5.0
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