Commit 971e5b35 authored Dec 18, 2007 by Steven Rostedt Committed by Ingo Molnar Dec 18, 2007

genirq: revert lazy irq disable for simple irqs



In commit 76d21601 lazy irq disabling
was implemented, and the simple irq handler had a masking set to it.

Remy Bohmer discovered that some devices in the ARM architecture
would trigger the mask, but never unmask it. His patch to do the
unmasking was questioned by Russell King about masking simple irqs
to begin with. Looking further, it was discovered that the problems
Remy was seeing was due to improper use of the simple handler by
devices, and he later submitted patches to fix those. But the issue
that was uncovered was that the simple handler should never mask.

This patch reverts the masking in the simple handler.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 213fde71

kernel/irq/chip.c

+2 −7

Original line number	Diff line number	Diff line
		@@ -297,18 +297,13 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc)

		if (unlikely(desc->status & IRQ_INPROGRESS))
		goto out_unlock;
		desc->status &= ~(IRQ_REPLAY \| IRQ_WAITING);
		kstat_cpu(cpu).irqs[irq]++;

		action = desc->action;
		if (unlikely(!action \|\| (desc->status & IRQ_DISABLED))) {
		if (desc->chip->mask)
		desc->chip->mask(irq);
		desc->status &= ~(IRQ_REPLAY \| IRQ_WAITING);
		desc->status \|= IRQ_PENDING;
		if (unlikely(!action \|\| (desc->status & IRQ_DISABLED)))
		goto out_unlock;
		}

		desc->status &= ~(IRQ_REPLAY \| IRQ_WAITING \| IRQ_PENDING);
		desc->status \|= IRQ_INPROGRESS;
		spin_unlock(&desc->lock);

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