[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>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/rtc/rtc-at91.c b/drivers/rtc/rtc-at91.c
index bd61e99540a3..5c8addcaf1fb 100644
--- a/drivers/rtc/rtc-at91.c
+++ b/drivers/rtc/rtc-at91.c
@@ -292,7 +292,8 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
                                         AT91_RTC_CALEV);
 
         ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
-                                IRQF_SHARED, "at91_rtc", pdev);
+                                IRQF_DISABLED | IRQF_SHARED,
+                                "at91_rtc", pdev);
         if (ret) {
                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
                                 AT91_ID_SYS);