From 8b1af56b29b9b81538b4d0d4fd9515618618ead1 Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@samba.org>
Date: Thu, 22 Dec 2005 21:55:37 +1100
Subject: [PATCH] powerpc: Fix i8259 cascade on pSeries with XICS interrupt
controller
It turns out that commit f9bd170a87948a9e077149b70fb192c563770fdf
broke the cascade from XICS to i8259 on pSeries machines; specifically
we ended up not ever doing the EOI on the XICS for the cascade. The
result was that interrupts from the serial ports (and presumably any
other devices using ISA interrupts) didn't get through. This fixes
it and also simplifies the code, by doing the EOI on the XICS in the
xics_get_irq routine after reading and acking the interrupt on the
i8259.
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/platforms/pseries/xics.c | 21 +++------------------
1 file changed, 3 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index 72ac18067ecef..0377decc07190 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -48,11 +48,6 @@ static struct hw_interrupt_type xics_pic = {
.set_affinity = xics_set_affinity
};
-static struct hw_interrupt_type xics_8259_pic = {
- .typename = " XICS/8259",
- .ack = xics_mask_and_ack_irq,
-};
-
/* This is used to map real irq numbers to virtual */
static struct radix_tree_root irq_map = RADIX_TREE_INIT(GFP_ATOMIC);
@@ -367,12 +362,7 @@ int xics_get_irq(struct pt_regs *regs)
/* for sanity, this had better be < NR_IRQS - 16 */
if (vec == xics_irq_8259_cascade_real) {
irq = i8259_irq(regs);
- if (irq == -1) {
- /* Spurious cascaded interrupt. Still must ack xics */
- xics_end_irq(irq_offset_up(xics_irq_8259_cascade));
-
- irq = -1;
- }
+ xics_end_irq(irq_offset_up(xics_irq_8259_cascade));
} else if (vec == XICS_IRQ_SPURIOUS) {
irq = -1;
} else {
@@ -542,6 +532,7 @@ void xics_init_IRQ(void)
xics_irq_8259_cascade_real = *ireg;
xics_irq_8259_cascade
= virt_irq_create_mapping(xics_irq_8259_cascade_real);
+ i8259_init(0, 0);
of_node_put(np);
}
@@ -565,12 +556,7 @@ void xics_init_IRQ(void)
#endif /* CONFIG_SMP */
}
- xics_8259_pic.enable = i8259_pic.enable;
- xics_8259_pic.disable = i8259_pic.disable;
- xics_8259_pic.end = i8259_pic.end;
- for (i = 0; i < 16; ++i)
- get_irq_desc(i)->handler = &xics_8259_pic;
- for (; i < NR_IRQS; ++i)
+ for (i = irq_offset_value(); i < NR_IRQS; ++i)
get_irq_desc(i)->handler = &xics_pic;
xics_setup_cpu();
@@ -590,7 +576,6 @@ static int __init xics_setup_i8259(void)
no_action, 0, "8259 cascade", NULL))
printk(KERN_ERR "xics_setup_i8259: couldn't get 8259 "
"cascade\n");
- i8259_init(0, 0);
}
return 0;
}
--
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