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authorJiri Kosina <jkosina@suse.cz>2007-11-28 16:22:03 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-11-29 09:24:54 -0800
commit8853c202b4a91713dbfb4d9b6e1c87cc2aa12392 (patch)
treea6c9621d3067eebc17c2ce53fa45e7513ee832a6 /drivers/rtc/interface.c
parent08b633070ad5fa17a837428a601c32cf3db6aafd (diff)
downloadlinux-8853c202b4a91713dbfb4d9b6e1c87cc2aa12392.tar.gz
RTC: convert mutex to bitfield
RTC code is using mutex to assure exclusive access to /dev/rtc.  This is
however wrong usage, as it leaves the mutex locked when returning into
userspace, which is unacceptable.

Convert rtc->char_lock into bit operation.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/interface.c')
-rw-r--r--drivers/rtc/interface.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index de0da545c7a1..a4f56e95cf96 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -293,7 +293,7 @@ int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
 		return -EINVAL;
 
 	/* Cannot register while the char dev is in use */
-	if (!(mutex_trylock(&rtc->char_lock)))
+	if (test_and_set_bit(RTC_DEV_BUSY, &rtc->flags))
 		return -EBUSY;
 
 	spin_lock_irq(&rtc->irq_task_lock);
@@ -303,7 +303,7 @@ int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
 	}
 	spin_unlock_irq(&rtc->irq_task_lock);
 
-	mutex_unlock(&rtc->char_lock);
+	clear_bit(RTC_DEV_BUSY, &rtc->flags);
 
 	return retval;
 }