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| author | Changhwan Youn <chaos.youn@samsung.com> | 2010-09-29 13:31:42 +0200 |
|---|---|---|
| committer | Kukjin Kim <kgene.kim@samsung.com> | 2010-10-21 00:52:18 +0200 |
| commit | 0c0f909689c8387265a3682d4205c063071ec36a (patch) | |
| tree | 3d341bd807e1bd050a393ee3ead44ff87bcda036 | |
| parent | ARM: S5PV310: Add support Watchdog Timer (diff) | |
| download | linux-0c0f909689c8387265a3682d4205c063071ec36a.tar.xz linux-0c0f909689c8387265a3682d4205c063071ec36a.zip | |
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: Junseok Jung <jundols.jung@samsung.com>
Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
| -rw-r--r-- | arch/arm/mach-s5pv310/irq-combiner.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/arch/arm/mach-s5pv310/irq-combiner.c b/arch/arm/mach-s5pv310/irq-combiner.c index 0f7052164f23..c3f88c3faf6c 100644 --- a/arch/arm/mach-s5pv310/irq-combiner.c +++ b/arch/arm/mach-s5pv310/irq-combiner.c @@ -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)) |