[PATCH 2/7] powerpc/kdump: Use chip->shutdown to disable IRQs

[Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>]

    powerpc/kdump: Use chip->shutdown to disable IRQs

    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: Kamalesh babulal <kamalesh@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/crash.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: b/arch/powerpc/kernel/crash.c
===================================================================
--- a/arch/powerpc/kernel/crash.c	2011-03-07 00:27:22.703086492 -0800
+++ b/arch/powerpc/kernel/crash.c	2011-03-07 00:27:49.659105563 -0800
@@ -382,7 +382,7 @@
			desc->chip->eoi(i);

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

	/*