[34-longterm 156/247] powerpc/kdump: Use chip->shutdown to disable IRQs

From: Paul Gortmaker
Date: Thu Jun 23 2011 - 14:00:05 EST

From: Anton Blanchard <anton@xxxxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 5d7a87217de48b234b3c8ff8a73059947d822e07 upstream.

I saw this in a kdump kernel:

IOMMU table initialized, virtual merging enabled
Interrupt 155954 (real) is invalid, disabling it.
Interrupt 155953 (real) is invalid, disabling it.

ie we took some spurious interrupts. default_machine_crash_shutdown tries
to disable all interrupt sources but uses chip->disable which maps to
the default action of:

static void default_disable(unsigned int irq)

If we use chip->shutdown, then we actually mask the IRQ:

static void default_shutdown(unsigned int irq)
struct irq_desc *desc = irq_to_desc(irq);

desc->status |= IRQ_MASKED;

Not sure why we don't implement a ->disable action for xics.c, or why
default_disable doesn't mask the interrupt.

Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
arch/powerpc/kernel/crash.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index fbe3c1c..0384376 100644
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -381,7 +381,7 @@ void default_machine_crash_shutdown(struct pt_regs *regs)

if (!(desc->status & IRQ_DISABLED))
- desc->chip->disable(i);
+ desc->chip->shutdown(i);


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