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| author | David Brownell <david-b@pacbell.net> | 2006-11-25 11:09:28 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-11-25 13:28:33 -0800 |
| commit | d728b1e69fd5829ec2ab2434381e5a268d4f684a (patch) | |
| tree | e11b3dea35247074628f04f5441e4a458bdbd86b /drivers/rtc/rtc-dev.c | |
| parent | 2601a46474db2dcbc08ee690e56f08a10abe65cb (diff) | |
| download | linux-d728b1e69fd5829ec2ab2434381e5a268d4f684a.tar.gz linux-d728b1e69fd5829ec2ab2434381e5a268d4f684a.tar.bz2 linux-d728b1e69fd5829ec2ab2434381e5a268d4f684a.zip | |
[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.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 3109865e8d73..814b9e1873f5 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; |