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Commit 0c0f9096 authored by Changhwan Youn's avatar Changhwan Youn Committed by Kukjin Kim
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ARM: S5PV310: Optimize interrupt source searching code 



It is reported by Junseok Jung that using clz instruction is
better instead of using for-loop to find the interrupt source.
This patch modifies interrupt source searching code using __ffs().
The __ffs() is implemented using clz instruction.

Suggested-by: default avatarJunseok Jung <jundols.jung@samsung.com>
Signed-off-by: default avatarChanghwan Youn <chaos.youn@samsung.com>
Signed-off-by: default avatarKukjin Kim <kgene.kim@samsung.com>
parent 8d75c912

arch/arm/mach-s5pv310/irq-combiner.c

+1 −5
Original line number Diff line number Diff line
@@ -66,11 +66,7 @@ static void combiner_handle_cascade_irq(unsigned int irq, struct irq_desc *desc) 
	if (status == 0)

		goto out;



	for (combiner_irq = 0; combiner_irq < 32; combiner_irq++) {

		if (status & 0x1)

			break;

		status >>= 1;

	}

	combiner_irq = __ffs(status);



	cascade_irq = combiner_irq + (chip_data->irq_offset & ~31);

	if (unlikely(cascade_irq >= NR_IRQS))