[PATCH 1/3] irqchip: orion: reverse irq handling priority

[Sebastian Hesselbarth]

Non-DT irq handlers were working through irq causes from most-significant
to least-significant bit, while DT irqchip driver does it the other way
round. This revealed some more HW issues on Kirkwood peripheral IP, where
spurious sdio irqs can happen although IP's irq enable registers are all
zero. Although, not directly related with the described issue, reverse
irq bit handling back to original order by replacing ffs() with fls().

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
---
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Jason Cooper <jason at lakedaemon.net>
Cc: Andrew Lunn <andrew at lunn.ch>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
---
 drivers/irqchip/irq-orion.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-orion.c b/drivers/irqchip/irq-orion.c
index e51d400..de30d5c 100644
--- a/drivers/irqchip/irq-orion.c
+++ b/drivers/irqchip/irq-orion.c
@@ -42,7 +42,7 @@ __exception_irq_entry orion_handle_irq(struct pt_regs *regs)
 		u32 stat = readl_relaxed(gc->reg_base + ORION_IRQ_CAUSE) &
 			gc->mask_cache;
 		while (stat) {
-			u32 hwirq = ffs(stat) - 1;
+			u32 hwirq = __fls(stat);
 			u32 irq = irq_find_mapping(orion_irq_domain,
 						   gc->irq_base + hwirq);
 			handle_IRQ(irq, regs);
@@ -116,7 +116,7 @@ static void orion_bridge_irq_handler(unsigned int irq, struct irq_desc *desc)
 		   gc->mask_cache;
 
 	while (stat) {
-		u32 hwirq = ffs(stat) - 1;
+		u32 hwirq = __fls(stat);
 
 		generic_handle_irq(irq_find_mapping(d, gc->irq_base + hwirq));
 		stat &= ~(1 << hwirq);
-- 
1.7.2.5