From d728b1e69fd5829ec2ab2434381e5a268d4f684a Mon Sep 17 00:00:00 2001 From: David Brownell Date: Sat, 25 Nov 2006 11:09:28 -0800 Subject: [PATCH] rtc class locking bugfixes I got a lockdep warning when running "rtctest" so I though it'd be good to see what was up. - The warning was for rtc->irq_task_lock, gotten from rtc_update_irq() by irq handlerss ... but in a handful of other cases, grabbed without blocking IRQs. - Some callers to rtc_update_irq() were not ensuring IRQs were blocked, yet the routine expects that; make sure all callers block IRQs. It would appear that RTC API tests haven't been part of anyone's kernel regression test suite recently, at least not with lockdep running. Signed-off-by: David Brownell Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/interface.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'drivers/rtc/interface.c') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 4783ec68fb3c..6f11f6dfdd9d 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -145,6 +145,13 @@ int rtc_set_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm) } EXPORT_SYMBOL_GPL(rtc_set_alarm); +/** + * rtc_update_irq - report RTC periodic, alarm, and/or update irqs + * @class_dev: the rtc's class device + * @num: how many irqs are being reported (usually one) + * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF + * Context: in_interrupt(), irqs blocked + */ void rtc_update_irq(struct class_device *class_dev, unsigned long num, unsigned long events) { @@ -201,12 +208,12 @@ int rtc_irq_register(struct class_device *class_dev, struct rtc_task *task) if (task == NULL || task->func == NULL) return -EINVAL; - spin_lock(&rtc->irq_task_lock); + spin_lock_irq(&rtc->irq_task_lock); if (rtc->irq_task == NULL) { rtc->irq_task = task; retval = 0; } - spin_unlock(&rtc->irq_task_lock); + spin_unlock_irq(&rtc->irq_task_lock); return retval; } @@ -216,10 +223,10 @@ void rtc_irq_unregister(struct class_device *class_dev, struct rtc_task *task) { struct rtc_device *rtc = to_rtc_device(class_dev); - spin_lock(&rtc->irq_task_lock); + spin_lock_irq(&rtc->irq_task_lock); if (rtc->irq_task == task) rtc->irq_task = NULL; - spin_unlock(&rtc->irq_task_lock); + spin_unlock_irq(&rtc->irq_task_lock); } EXPORT_SYMBOL_GPL(rtc_irq_unregister); -- cgit v1.2.3