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

Paul Gortmaker
2011-06-23T17:59:38Z

From: Anton Blanchard <anton@samba.org>

-------------------
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->chip->mask(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@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
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)
desc->chip->eoi(i);

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

/*
--
1.7.4.4