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Date: Thu, 20 Jan 2011 15:26:12 -0800
From: John Stultz <john.stultz@...aro.org>
To: LKML <linux-kernel@...r.kernel.org>
Cc: John Stultz <john.stultz@...aro.org>,
Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 1/2] 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: David Daney <ddaney@...iumnetworks.com>
Reported-by: Andreas Schwab <schwab@...ux-m68k.org>
Reported-by: Geert Uytterhoeven <geert@...ux-m68k.org>
Diagnosed-by: David Daney <ddaney@...iumnetworks.com>
Tested-by: David Daney <ddaney@...iumnetworks.com>
CC: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
drivers/rtc/interface.c | 49 ++++++++++++++++++++++++++--------------------
include/linux/rtc.h | 2 -
2 files changed, 28 insertions(+), 23 deletions(-)
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 90384b9..f1ba2c6 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -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;
}
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 3c995b4..bd4fbc3 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -246,8 +246,6 @@ 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);
--
1.7.3.2.146.gca209
--
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