On 08/08/2017 02:52 PM, Marc Zyngier wrote:
On 08/08/17 10:04, Alim Akhtar wrote:
Skip check for online cpu mask when setting irq affinity of per cpu timer
during early startup of not yet online cpu.

Signed-off-by: Shaik Ameer Basha <shaik.am...@samsung.com>
Signed-off-by: Aswani Reddy <aswani.re...@samsung.com>
Signed-off-by: Alim Akhtar <alim.akh...@samsung.com>
---
  drivers/irqchip/irq-gic-v3.c | 7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

Currently when non boot CPUs comes up and if setting of IRQ affinity gets called
before cpu online status gets updated, gic_mpidr_to_affinity() returns
undesirable cpu number. Using __force__ flag ignore cpu_online_mask and setup
the intended cpu affinity for the irq.

The same approch is used in gicv2
(commit: ffde1de64012c: irqchip: Gic: Support forced affinity setting)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index dbffb7a..c238c64 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -640,11 +640,16 @@ static void gic_smp_init(void)
  static int gic_set_affinity(struct irq_data *d, const struct cpumask 
*mask_val,
                            bool force)
  {
-       unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
+       unsigned int cpu;
        void __iomem *reg;
        int enabled;
        u64 val;
+ if (!force)
+               cpu = cpumask_any_and(mask_val, cpu_online_mask);
+       else
+               cpu = cpumask_first(mask_val);
+
        if (cpu >= nr_cpu_ids)
                return -EINVAL;

See

https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/irqchip-4.13&id=65a30f8b300107266f316d550f060ccc186201a3


Thanks Marc for above link. Is this already queued in some tree? I can't find this is linux-next.

        M.

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