From cbeb4b7ad5346516d2ee726395eb5722b25a0a01 Mon Sep 17 00:00:00 2001
From: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Date: Tue, 25 Jan 2011 15:07:16 -0800
Subject: [PATCH] parport: make lockdep happy with waitlist_lock
parport_unregister_device() should never be used when interrupts are
enabled in hardware and irq handler is registered so there is no need to
disable interrupts when using waitlist_lock. But there is no way to
explain this subtle semantics to lockdep analyzer.
So disable interrupts here too to simplify things. The price is
negligible.
Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/parport/share.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index a2d9d1e59260..a848e02e6be3 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -678,7 +678,7 @@ void parport_unregister_device(struct pardevice *dev)
/* Make sure we haven't left any pointers around in the wait
* list. */
- spin_lock (&port->waitlist_lock);
+ spin_lock_irq(&port->waitlist_lock);
if (dev->waitprev || dev->waitnext || port->waithead == dev) {
if (dev->waitprev)
dev->waitprev->waitnext = dev->waitnext;
@@ -689,7 +689,7 @@ void parport_unregister_device(struct pardevice *dev)
else
port->waittail = dev->waitprev;
}
- spin_unlock (&port->waitlist_lock);
+ spin_unlock_irq(&port->waitlist_lock);
kfree(dev->state);
kfree(dev);
--
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