Commit aa0be0f4 authored by John Stultz's avatar John Stultz Committed by Thomas Gleixner
Browse files

RTC: Propagate error handling via rtc_timer_enqueue properly 



In cases where RTC hardware does not support alarms, the virtualized
RTC interfaces did not have a way to propagate the error up to userland.

This patch extends rtc_timer_enqueue so it catches errors from the hardware
and returns them upwards to the virtualized interfaces. To simplify error
handling, it also internalizes the management of the timer->enabled bit
into rtc_timer_enqueue and rtc_timer_remove.

Also makes rtc_timer_enqueue and rtc_timer_remove static.

Reported-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Reported-by: default avatarAndreas Schwab <schwab@linux-m68k.org>
Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Diagnosed-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Tested-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
LKML-Reference: <1295565973-14358-1-git-send-email-john.stultz@linaro.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent db6b175f

drivers/rtc/interface.c

+28 −21
Original line number Diff line number Diff line
@@ -16,6 +16,9 @@ 
#include <linux/log2.h>

#include <linux/workqueue.h>



static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);

static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);



static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)

{

	int err;
@@ -175,16 +178,14 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) 
		return err;

	if (rtc->aie_timer.enabled) {

		rtc_timer_remove(rtc, &rtc->aie_timer);

		rtc->aie_timer.enabled = 0;

	}

	rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);

	rtc->aie_timer.period = ktime_set(0, 0);

	if (alarm->enabled) {

		rtc->aie_timer.enabled = 1;

		rtc_timer_enqueue(rtc, &rtc->aie_timer);

		err = rtc_timer_enqueue(rtc, &rtc->aie_timer);

	}

	mutex_unlock(&rtc->ops_lock);

	return 0;

	return err;

}

EXPORT_SYMBOL_GPL(rtc_set_alarm);
@@ -195,15 +196,15 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
		return err;



	if (rtc->aie_timer.enabled != enabled) {

		if (enabled) {

			rtc->aie_timer.enabled = 1;

			rtc_timer_enqueue(rtc, &rtc->aie_timer);

		} else {

		if (enabled)

			err = rtc_timer_enqueue(rtc, &rtc->aie_timer);

		else

			rtc_timer_remove(rtc, &rtc->aie_timer);

			rtc->aie_timer.enabled = 0;

		}

	}



	if (err)

		return err;



	if (!rtc->ops)

		err = -ENODEV;

	else if (!rtc->ops->alarm_irq_enable)
@@ -235,12 +236,9 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
		now = rtc_tm_to_ktime(tm);

		rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);

		rtc->uie_rtctimer.period = ktime_set(1, 0);

		rtc->uie_rtctimer.enabled = 1;

		rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);

	} else {

		err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);

	} else

		rtc_timer_remove(rtc, &rtc->uie_rtctimer);

		rtc->uie_rtctimer.enabled = 0;

	}



out:

	mutex_unlock(&rtc->ops_lock);
@@ -488,10 +486,13 @@ EXPORT_SYMBOL_GPL(rtc_irq_set_freq); 
 * Enqueues a timer onto the rtc devices timerqueue and sets

 * the next alarm event appropriately.

 *

 * Sets the enabled bit on the added timer.

 *

 * Must hold ops_lock for proper serialization of timerqueue

 */

void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)

static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)

{

	timer->enabled = 1;

	timerqueue_add(&rtc->timerqueue, &timer->node);

	if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {

		struct rtc_wkalrm alarm;
@@ -501,7 +502,13 @@ void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) 
		err = __rtc_set_alarm(rtc, &alarm);

		if (err == -ETIME)

			schedule_work(&rtc->irqwork);

		else if (err) {

			timerqueue_del(&rtc->timerqueue, &timer->node);

			timer->enabled = 0;

			return err;

		}

	}

	return 0;

}



/**
@@ -512,13 +519,15 @@ void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) 
 * Removes a timer onto the rtc devices timerqueue and sets

 * the next alarm event appropriately.

 *

 * Clears the enabled bit on the removed timer.

 *

 * Must hold ops_lock for proper serialization of timerqueue

 */

void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)

static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)

{

	struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);

	timerqueue_del(&rtc->timerqueue, &timer->node);



	timer->enabled = 0;

	if (next == &timer->node) {

		struct rtc_wkalrm alarm;

		int err;
@@ -626,8 +635,7 @@ int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer, 
	timer->node.expires = expires;

	timer->period = period;



	timer->enabled = 1;

	rtc_timer_enqueue(rtc, timer);

	ret = rtc_timer_enqueue(rtc, timer);



	mutex_unlock(&rtc->ops_lock);

	return ret;
@@ -645,7 +653,6 @@ int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer) 
	mutex_lock(&rtc->ops_lock);

	if (timer->enabled)

		rtc_timer_remove(rtc, timer);

	timer->enabled = 0;

	mutex_unlock(&rtc->ops_lock);

	return ret;

}

include/linux/rtc.h

+0 −2
Original line number Diff line number Diff line
@@ -244,8 +244,6 @@ int rtc_register(rtc_task_t *task); 
int rtc_unregister(rtc_task_t *task);

int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);



void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);

void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);

void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data);

int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer,

			ktime_t expires, ktime_t period);

CRA Git | Maintained and supported by SUSTech CRA and CCSE