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>

diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index a2d9d1e59260eab17097e0a12f16908eed26c552..a848e02e6be3d4537b5dd94c7017ec799cf7becb 100644 (file)
--- 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);