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authorDavid Brownell <david-b@pacbell.net>2006-11-25 11:09:28 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-11-25 13:28:33 -0800
commitd728b1e69fd5829ec2ab2434381e5a268d4f684a (patch)
treee11b3dea35247074628f04f5441e4a458bdbd86b /drivers/rtc/rtc-dev.c
parent2601a46474db2dcbc08ee690e56f08a10abe65cb (diff)
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[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 <dbrownell@users.sourceforge.net> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/rtc/rtc-dev.c')
-rw-r--r--drivers/rtc/rtc-dev.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 3109865e8d7..814b9e1873f 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -61,7 +61,9 @@ static void rtc_uie_task(void *data)
int err;
err = rtc_read_time(&rtc->class_dev, &tm);
- spin_lock_irq(&rtc->irq_lock);
+
+ local_irq_disable();
+ spin_lock(&rtc->irq_lock);
if (rtc->stop_uie_polling || err) {
rtc->uie_task_active = 0;
} else if (rtc->oldsecs != tm.tm_sec) {
@@ -74,11 +76,11 @@ static void rtc_uie_task(void *data)
} else if (schedule_work(&rtc->uie_task) == 0) {
rtc->uie_task_active = 0;
}
- spin_unlock_irq(&rtc->irq_lock);
+ spin_unlock(&rtc->irq_lock);
if (num)
rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF);
+ local_irq_enable();
}
-
static void rtc_uie_timer(unsigned long data)
{
struct rtc_device *rtc = (struct rtc_device *)data;
@@ -238,10 +240,10 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
/* avoid conflicting IRQ users */
if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) {
- spin_lock(&rtc->irq_task_lock);
+ spin_lock_irq(&rtc->irq_task_lock);
if (rtc->irq_task)
err = -EBUSY;
- spin_unlock(&rtc->irq_task_lock);
+ spin_unlock_irq(&rtc->irq_task_lock);
if (err < 0)
return err;