powerpc/powernv: Check for IRQHAPPENED before sleeping

Commit 8d6f7c5a: "powerpc/powernv: Make it possible to skip the IRQHAPPENED
check in power7_nap()" added code that prevents cpus from checking for
pending interrupts just before entering sleep state, which is wrong. These
interrupts are delivered during the soft irq disabled state of the cpu.

A cpu cannot enter any idle state with pending interrupts because they will
never be serviced until the next time the cpu is woken up by some other
interrupt. Its only then that the pending interrupts are replayed. This can result
in device timeouts or warnings about this cpu being stuck.

This patch fixes ths issue by ensuring that cpus check for pending interrupts
just before entering any idle state as long as they are not in the path of split
core operations.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S
index 2480256272d4b5c84cd9654b48498f9d1bd9d519..5cf3d367190df77cdde609d5a926ce3269b20a4a 100644 (file)
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -131,7 +131,7 @@ _GLOBAL(power7_nap)
 
 _GLOBAL(power7_sleep)
        li      r3,1
-       li      r4,0
+       li      r4,1
        b       power7_powersave_common
        /* No return */