From 38e0533ce87a58e25f959e6d0958478b6a137794 Mon Sep 17 00:00:00 2001
From: Ben Dooks <ben-linux@fluff.org>
Date: Thu, 28 Sep 2006 20:40:50 +0100
Subject: [PATCH] [ARM] 3871/1: S3C24XX: Fix ordering of EINT4..23

The demux code for the IRQ EINTs above 3 was
using find last set instead of finding first
set.

Also fix it so that we only check EINT4..7
when the parent EINT4t7 goes off, and the
8..23 when EINT8t23 goes off.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-s3c2410/irq.c | 44 ++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-s3c2410/irq.c b/arch/arm/mach-s3c2410/irq.c
index 9c7463bf8f8..0ecfef3c751 100644
--- a/arch/arm/mach-s3c2410/irq.c
+++ b/arch/arm/mach-s3c2410/irq.c
@@ -569,18 +569,46 @@ s3c_irq_demux_uart2(unsigned int irq,
 }
 
 static void
-s3c_irq_demux_extint(unsigned int irq,
-		     struct irqdesc *desc,
-		     struct pt_regs *regs)
+s3c_irq_demux_extint8(unsigned int irq,
+		      struct irqdesc *desc,
+		      struct pt_regs *regs)
 {
 	unsigned long eintpnd = __raw_readl(S3C24XX_EINTPEND);
 	unsigned long eintmsk = __raw_readl(S3C24XX_EINTMASK);
 
 	eintpnd &= ~eintmsk;
+	eintpnd &= ~0xff;	/* ignore lower irqs */
 
-	if (eintpnd) {
-		irq = fls(eintpnd);
-		irq += (IRQ_EINT4 - (4 + 1));
+	/* we may as well handle all the pending IRQs here */
+
+	while (eintpnd) {
+		irq = __ffs(eintpnd);
+		eintpnd &= ~(1<<irq);
+
+		irq += (IRQ_EINT4 - 4);
+		desc_handle_irq(irq, irq_desc + irq, regs);
+	}
+
+}
+
+static void
+s3c_irq_demux_extint4t7(unsigned int irq,
+			struct irqdesc *desc,
+			struct pt_regs *regs)
+{
+	unsigned long eintpnd = __raw_readl(S3C24XX_EINTPEND);
+	unsigned long eintmsk = __raw_readl(S3C24XX_EINTMASK);
+
+	eintpnd &= ~eintmsk;
+	eintpnd &= 0xff;	/* only lower irqs */
+
+	/* we may as well handle all the pending IRQs here */
+
+	while (eintpnd) {
+		irq = __ffs(eintpnd);
+		eintpnd &= ~(1<<irq);
+
+		irq += (IRQ_EINT4 - 4);
 
 		desc_handle_irq(irq, irq_desc + irq, regs);
 	}
@@ -727,8 +755,8 @@ void __init s3c24xx_init_irq(void)
 
 	/* setup the cascade irq handlers */
 
-	set_irq_chained_handler(IRQ_EINT4t7, s3c_irq_demux_extint);
-	set_irq_chained_handler(IRQ_EINT8t23, s3c_irq_demux_extint);
+	set_irq_chained_handler(IRQ_EINT4t7, s3c_irq_demux_extint4t7);
+	set_irq_chained_handler(IRQ_EINT8t23, s3c_irq_demux_extint8);
 
 	set_irq_chained_handler(IRQ_UART0, s3c_irq_demux_uart0);
 	set_irq_chained_handler(IRQ_UART1, s3c_irq_demux_uart1);
-- 
2.41.0