aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorSteve Twiss <stwiss.opensource@diasemi.com>2015-12-08 16:28:39 +0000
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2015-12-20 13:39:29 +0100
commit77535acedc26627f16a1a39c1471f942689fe11e (patch)
treee266f91bdad8c50c71d6cb78e56fdbf422935139
parentrtc: rk808: Compensate for Rockchip calendar deviation on November 31st (diff)
downloadlinux-dev-77535acedc26627f16a1a39c1471f942689fe11e.tar.xz
linux-dev-77535acedc26627f16a1a39c1471f942689fe11e.zip
rtc: da9063: fix access ordering error during RTC interrupt at system power on
This fix alters the ordering of the IRQ and device registrations in the RTC driver probe function. This change will apply to the RTC driver that supports both DA9063 and DA9062 PMICs. A problem could occur with the existing RTC driver if: A system is started from a cold boot using the PMIC RTC IRQ to initiate a power on operation. For instance, if an RTC alarm is used to start a platform from power off. The existing driver IRQ is requested before the device has been properly registered. i.e. ret = devm_request_threaded_irq() comes before rtc->rtc_dev = devm_rtc_device_register(); In this case, the interrupt can be called before the device has been registered and the handler can be called immediately. The IRQ handler da9063_alarm_event() contains the function call rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); which in turn tries to access the unavailable rtc->rtc_dev. The fix is to reorder the functions inside the RTC probe. The IRQ is requested after the RTC device resource has been registered so that get_irq_byname is the last thing to happen. Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
-rw-r--r--drivers/rtc/rtc-da9063.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/rtc/rtc-da9063.c b/drivers/rtc/rtc-da9063.c
index 284b587da65c..d6c853bbfa9f 100644
--- a/drivers/rtc/rtc-da9063.c
+++ b/drivers/rtc/rtc-da9063.c
@@ -483,24 +483,23 @@ static int da9063_rtc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, rtc);
+ rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, DA9063_DRVNAME_RTC,
+ &da9063_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc->rtc_dev))
+ return PTR_ERR(rtc->rtc_dev);
+
+ da9063_data_to_tm(data, &rtc->alarm_time, rtc);
+ rtc->rtc_sync = false;
+
irq_alarm = platform_get_irq_byname(pdev, "ALARM");
ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
da9063_alarm_event,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
"ALARM", rtc);
- if (ret) {
+ if (ret)
dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
irq_alarm, ret);
- return ret;
- }
-
- rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, DA9063_DRVNAME_RTC,
- &da9063_rtc_ops, THIS_MODULE);
- if (IS_ERR(rtc->rtc_dev))
- return PTR_ERR(rtc->rtc_dev);
- da9063_data_to_tm(data, &rtc->alarm_time, rtc);
- rtc->rtc_sync = false;
return ret;
}