Commit b42172fc authored Nov 22, 2006 by Linus Torvalds

Don't call "note_interrupt()" with irq descriptor lock held



This reverts commit f72fa707, and solves
the problem that it tried to fix by simply making "__do_IRQ()" call the
note_interrupt() function without the lock held, the way everybody else
does.

It should be noted that all interrupt handling code must never allow the
descriptor actors to be entered "recursively" (that's why we do all the
magic IRQ_PENDING stuff in the first place), so there actually is
exclusion at that much higher level, even in the absense of locking.

Acked-by: Vivek Goyal <vgoyal@in.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 0f9005a6

kernel/irq/handle.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -231,10 +231,10 @@ fastcall unsigned int __do_IRQ(unsigned int irq)
		spin_unlock(&desc->lock);

		action_ret = handle_IRQ_event(irq, action);

		spin_lock(&desc->lock);
		if (!noirqdebug)
		note_interrupt(irq, desc, action_ret);

		spin_lock(&desc->lock);
		if (likely(!(desc->status & IRQ_PENDING)))
		break;
		desc->status &= ~IRQ_PENDING;

kernel/irq/spurious.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -147,11 +147,7 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
		if (unlikely(irqfixup)) {
		/* Don't punish working computers */
		if ((irqfixup == 2 && irq == 0) \|\| action_ret == IRQ_NONE) {
		int ok;

		spin_unlock(&desc->lock);
		ok = misrouted_irq(irq);
		spin_lock(&desc->lock);
		int ok = misrouted_irq(irq);
		if (action_ret == IRQ_NONE)
		desc->irqs_unhandled -= ok;
		}

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