Re: [PATCH v3] irqchip/gic-v3-its: fix ITS queue timeout

[Marc Zyngier]

On 11/06/18 13:25, Yang Yingliang wrote:
> On a NUMA system, if an ITS is local to an offline
> node, the ITS driver may pick an offline CPU to bind
> the LPI. In this case, we need to pick an online CPU.
> But on some systems, binding LPI to non-local node
> CPU will cause deadlock. In this case, we don't
> bind the LPI to any online CPU and return an error code.
> 
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
>  drivers/irqchip/irq-gic-v3-its.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 5416f2b..137c433 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -2309,7 +2309,13 @@ static int its_irq_domain_activate(struct irq_domain *domain,
>  		cpu_mask = cpumask_of_node(its_dev->its->numa_node);
>  
>  	/* Bind the LPI to the first possible CPU */
> -	cpu = cpumask_first(cpu_mask);
> +	cpu = cpumask_first_and(cpu_mask, cpu_online_mask);
> +	if (cpu >= nr_cpu_ids) {
> +		if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144)
> +			return -EINVAL;
> +
> +		cpu = cpumask_first(cpu_online_mask);
> +	}
>  	its_dev->event_map.col_map[event] = cpu;
>  	irq_data_update_effective_affinity(d, cpumask_of(cpu));
>  
> 

Queued as a fix for 4.18 with a slightly updated change-log and a cc to
stable.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...