From 586e76ea0975340dd826e36522ac162e83d90962 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 27 Apr 2012 12:56:24 +0100 Subject: [PATCH] ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQs commit 5e7371ded05adfcfcee44a8bc070bfc37979b8f2 upstream. When a CPU is hotplugged off, we migrate any IRQs currently affine to it away and onto another online CPU by calling the irq_set_affinity function of the relevant interrupt controller chip. This function returns either IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY, to indicate whether irq_data.affinity was updated. If we are forcefully migrating an interrupt (because the affinity mask no longer identifies any online CPUs) then we should update the IRQ affinity mask to reflect the new CPU set. Failure to do so can potentially leave /proc/irq/n/smp_affinity identifying only offline CPUs, which may confuse userspace IRQ balancing daemons. This patch updates migrate_one_irq to copy the affinity mask when the interrupt chip returns IRQ_SET_MASK_OK after forcefully changing the affinity of an interrupt. Reported-by: Leif Lindholm Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Ben Hutchings --- arch/arm/kernel/irq.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 3efd82cc95f0..87c8be59a25a 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -156,10 +156,10 @@ static bool migrate_one_irq(struct irq_desc *desc) } c = irq_data_get_irq_chip(d); - if (c->irq_set_affinity) - c->irq_set_affinity(d, affinity, true); - else + if (!c->irq_set_affinity) pr_debug("IRQ%u: unable to set affinity\n", d->irq); + else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret) + cpumask_copy(d->affinity, affinity); return ret; } -- 2.39.5