[rtc-linux] [PATCH v4 7/7] rtc: ds3232: use rtc->ops_lock to protect alarm operations
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: 2016-03-06 15:28:29
Subsystem:
real time clock (rtc) subsystem, the rest · Maintainers:
Alexandre Belloni, Linus Torvalds
ds3232->mutex is used to protect for alarm operations which need to access status and control registers. But we can use rtc->ops_lock instead. rtc->ops_lock is held when most of rtc_class_ops methods are called, so we only need to explicitly acquire it from irq handler in order to protect form concurrent accesses. 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 | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-)
diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index dacced5..b99cbe4 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c@@ -52,11 +52,6 @@ struct ds3232 { int irq; struct rtc_device *rtc; - /* The mutex protects alarm operations, and prevents a race - * between the enable_irq() in the workqueue and the free_irq() - * in the remove function. - */ - struct mutex mutex; bool suspended; };
@@ -187,8 +182,6 @@ static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) int ret; u8 buf[4]; - mutex_lock(&ds3232->mutex); - ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); if (ret) goto out;
@@ -215,7 +208,6 @@ static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) ret = 0; out: - mutex_unlock(&ds3232->mutex); return ret; }
@@ -233,8 +225,6 @@ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) if (ds3232->irq <= 0) return -EINVAL; - mutex_lock(&ds3232->mutex); - buf[0] = bin2bcd(alarm->time.tm_sec); buf[1] = bin2bcd(alarm->time.tm_min); buf[2] = bin2bcd(alarm->time.tm_hour);
@@ -267,7 +257,6 @@ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); } out: - mutex_unlock(&ds3232->mutex); return ret; }
@@ -277,11 +266,9 @@ static int ds3232_update_alarm(struct device *dev, unsigned int enabled) int control; int ret; - mutex_lock(&ds3232->mutex); - ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); if (ret) - goto unlock; + return ret; if (enabled) /* enable alarm1 interrupt */
@@ -291,9 +278,6 @@ static int ds3232_update_alarm(struct device *dev, unsigned int enabled) control &= ~(DS3232_REG_CR_A1IE); ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); -unlock: - mutex_unlock(&ds3232->mutex); - return ret; }
@@ -311,10 +295,11 @@ static irqreturn_t ds3232_irq(int irq, void *dev_id) { struct device *dev = dev_id; struct ds3232 *ds3232 = dev_get_drvdata(dev); + struct mutex *lock = &ds3232->rtc->ops_lock; int ret; int stat, control; - mutex_lock(&ds3232->mutex); + mutex_lock(lock); ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); if (ret)
@@ -352,7 +337,7 @@ static irqreturn_t ds3232_irq(int irq, void *dev_id) } unlock: - mutex_unlock(&ds3232->mutex); + mutex_unlock(lock); return IRQ_HANDLED; }
@@ -380,8 +365,6 @@ static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq, ds3232->dev = dev; dev_set_drvdata(dev, ds3232); - mutex_init(&ds3232->mutex); - ret = ds3232_check_rtc_status(dev); if (ret) return ret;
--
2.5.0
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