[ARM] 3918/1: ixp4xx irq-chip rework

This is a rework of the ixp4xx irq_chip implementation.  The use of
two irq_chip structures and potentially switching between them is a
violation of the intended use of the IRQ framework.  The current
implementation does not work with current in-kernel spinlock debugging
or lockdep due to lock recursion problems caused by calling
set_irq_chip/handler from within the chip's set_irq_type().

This patch goes back to using one irq_chip structure and handling the
differences between edge/level, normal/GPIO interrupts inside the
ack/mask/unmask routines themselves.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Deepak Saxena <dsaxena@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 22 insertions, 38 deletions

diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index c7513f6eb50c..fbe288a8da65 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -86,7 +86,8 @@ enum ixp4xx_irq_type {
         IXP4XX_IRQ_LEVEL, IXP4XX_IRQ_EDGE
 };
 
-static void ixp4xx_config_irq(unsigned irq, enum ixp4xx_irq_type type);
+/* Each bit represents an IRQ: 1: edge-triggered, 0: level triggered */
+static unsigned long long ixp4xx_irq_edge = 0;
 
 /*
  * IRQ -> GPIO mapping table
@@ -135,7 +136,11 @@ static int ixp4xx_set_irq_type(unsigned int irq, unsigned int type)
         default:
                 return -EINVAL;
         }
-        ixp4xx_config_irq(irq, irq_type);
+
+        if (irq_type == IXP4XX_IRQ_EDGE)
+                ixp4xx_irq_edge |= (1 << irq);
+        else
+                ixp4xx_irq_edge &= ~(1 << irq);
 
         if (line >= 8) {        /* pins 8-15 */
                 line -= 8;
@@ -167,14 +172,6 @@ static void ixp4xx_irq_mask(unsigned int irq)
                 *IXP4XX_ICMR &= ~(1 << irq);
 }
 
-static void ixp4xx_irq_unmask(unsigned int irq)
-{
-        if (cpu_is_ixp46x() && irq >= 32)
-                *IXP4XX_ICMR2 |= (1 << (irq - 32));
-        else
-                *IXP4XX_ICMR |= (1 << irq);
-}
-
 static void ixp4xx_irq_ack(unsigned int irq)
 {
         int line = (irq < 32) ? irq2gpio[irq] : -1;
@@ -187,41 +184,25 @@ static void ixp4xx_irq_ack(unsigned int irq)
  * Level triggered interrupts on GPIO lines can only be cleared when the
  * interrupt condition disappears.
  */
-static void ixp4xx_irq_level_unmask(unsigned int irq)
+static void ixp4xx_irq_unmask(unsigned int irq)
 {
-        ixp4xx_irq_ack(irq);
-        ixp4xx_irq_unmask(irq);
-}
+        if (!(ixp4xx_irq_edge & (1 << irq)))
+                ixp4xx_irq_ack(irq);
 
-static struct irqchip ixp4xx_irq_level_chip = {
-        .ack            = ixp4xx_irq_mask,
-        .mask           = ixp4xx_irq_mask,
-        .unmask         = ixp4xx_irq_level_unmask,
-        .set_type       = ixp4xx_set_irq_type,
-};
+        if (cpu_is_ixp46x() && irq >= 32)
+                *IXP4XX_ICMR2 |= (1 << (irq - 32));
+        else
+                *IXP4XX_ICMR |= (1 << irq);
+}
 
-static struct irqchip ixp4xx_irq_edge_chip = {
+static struct irqchip ixp4xx_irq_chip = {
+        .name           = "IXP4xx",
         .ack            = ixp4xx_irq_ack,
         .mask           = ixp4xx_irq_mask,
         .unmask         = ixp4xx_irq_unmask,
         .set_type       = ixp4xx_set_irq_type,
 };
 
-static void ixp4xx_config_irq(unsigned irq, enum ixp4xx_irq_type type)
-{
-        switch (type) {
-        case IXP4XX_IRQ_LEVEL:
-                set_irq_chip(irq, &ixp4xx_irq_level_chip);
-                set_irq_handler(irq, do_level_IRQ);
-                break;
-        case IXP4XX_IRQ_EDGE:
-                set_irq_chip(irq, &ixp4xx_irq_edge_chip);
-                set_irq_handler(irq, do_edge_IRQ);
-                break;
-        }
-        set_irq_flags(irq, IRQF_VALID);
-}
-
 void __init ixp4xx_init_irq(void)
 {
         int i = 0;
@@ -241,8 +222,11 @@ void __init ixp4xx_init_irq(void)
         }
 
         /* Default to all level triggered */
-        for(i = 0; i < NR_IRQS; i++)
-                ixp4xx_config_irq(i, IXP4XX_IRQ_LEVEL);
+        for(i = 0; i < NR_IRQS; i++) {
+                set_irq_chip(i, &ixp4xx_irq_chip);
+                set_irq_handler(i, do_level_IRQ);
+                set_irq_flags(i, IRQF_VALID);
+        }
 }