From 7c0482e3d055e5de056d3c693b821e39205b99ae Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 10 May 2012 16:12:38 +0000 Subject: 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 --- arch/powerpc/kernel/irq.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'arch/powerpc/kernel/irq.c') 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); /* -- cgit v1.2.3