Commit 4a649903 authored by John Stultz's avatar John Stultz
Browse files

rtc: Provide flag for rtc devices that don't support UIE 



Richard Weinberger noticed that on some RTC hardware that
doesn't support UIE mode, due to coarse granular alarms
(like 1minute resolution), the current virtualized RTC
support doesn't properly error out when UIE is enabled.

Instead the current code queues an alarm for the next second,
but it won't fire until up to a miniute later.

This patch provides a generic way to flag this sort of hardware
and fixes the issue on the mpc5121 where Richard noticed the
problem.

CC: stable@vger.kernel.org
Reported-by: default avatarRichard Weinberger <richard@nod.at>
Tested-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 74a622be

drivers/rtc/interface.c

+5 −0
Original line number Original line Diff line number Diff line
@@ -458,6 +458,11 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
	if (rtc->uie_rtctimer.enabled == enabled)

	if (rtc->uie_rtctimer.enabled == enabled)

		goto out;

		goto out;





	if (rtc->uie_unsupported) {

		err = -EINVAL;

		goto out;

	}



	if (enabled) {

	if (enabled) {

		struct rtc_time tm;

		struct rtc_time tm;

		ktime_t now, onesec;

		ktime_t now, onesec;

drivers/rtc/rtc-mpc5121.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -360,6 +360,8 @@ static int __devinit mpc5121_rtc_probe(struct platform_device *op) 
						&mpc5200_rtc_ops, THIS_MODULE);

						&mpc5200_rtc_ops, THIS_MODULE);

	}

	}





	rtc->rtc->uie_unsupported = 1;



	if (IS_ERR(rtc->rtc)) {

	if (IS_ERR(rtc->rtc)) {

		err = PTR_ERR(rtc->rtc);

		err = PTR_ERR(rtc->rtc);

		goto out_free_irq;

		goto out_free_irq;

include/linux/rtc.h

+2 −1
Original line number Original line Diff line number Diff line
@@ -202,7 +202,8 @@ struct rtc_device 
	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */

	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */

	int pie_enabled;

	int pie_enabled;

	struct work_struct irqwork;

	struct work_struct irqwork;



	/* Some hardware can't support UIE mode */

	int uie_unsupported;





#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL

	struct work_struct uie_task;

	struct work_struct uie_task;

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