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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-05-10 16:12:38 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-05-12 09:40:41 +1000
commit7c0482e3d055e5de056d3c693b821e39205b99ae (patch)
treead8d3ff6965d675c6bd255c5665deab7fba5df9f /arch/powerpc/kernel/irq.c
parent4e25651b70b8d6ded7229ead8181619e121b648d (diff)
powerpc/irq: Fix another case of lazy IRQ state getting out of sync
So we have another case of paca->irq_happened getting out of sync with the HW irq state. This can happen when a perfmon interrupt occurs while soft disabled, as it will return to a soft disabled but hard enabled context while leaving a stale PACA_IRQ_HARD_DIS flag set. This patch fixes it, and also adds a test for the condition of those flags being out of sync in arch_local_irq_restore() when CONFIG_TRACE_IRQFLAGS is enabled. This helps catching those gremlins faster (and so far I can't seem see any anymore, so that's good news). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
-rw-r--r--arch/powerpc/kernel/irq.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c6c6f3b7f8cd..641da9e868ce 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -229,6 +229,19 @@ notrace void arch_local_irq_restore(unsigned long en)
*/
if (unlikely(irq_happened != PACA_IRQ_HARD_DIS))
__hard_irq_disable();
+#ifdef CONFIG_TRACE_IRQFLAG
+ else {
+ /*
+ * We should already be hard disabled here. We had bugs
+ * where that wasn't the case so let's dbl check it and
+ * warn if we are wrong. Only do that when IRQ tracing
+ * is enabled as mfmsr() can be costly.
+ */
+ if (WARN_ON(mfmsr() & MSR_EE))
+ __hard_irq_disable();
+ }
+#endif /* CONFIG_TRACE_IRQFLAG */
+
set_soft_enabled(0);
/*