Re: [PATCH 1/2] irqchip/sifive-plic: Enable or disable interrupt based on its previous setting

From: Anup Patel
Date: Mon Oct 12 2020 - 13:02:54 EST


On Mon, Oct 12, 2020 at 7:27 PM Greentime Hu <greentime.hu@xxxxxxxxxx> wrote:
>
> It will always enable the interrupt after calling plic_set_affinity()
> however it should set to its previous setting. Staying disabled or enabled.
>
> This patch can also fix this pwm hang issue in Unleashed board.
>
> [ 919.015783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
> [ 919.020922] rcu: 0-...0: (0 ticks this GP)
> idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=105807
> [ 919.030295] (detected by 1, t=225825 jiffies, g=1561, q=3496)
> [ 919.036109] Task dump for CPU 0:
> [ 919.039321] kworker/0:1 R running task 0 30 2 0x00000008
> [ 919.046359] Workqueue: events set_brightness_delayed
> [ 919.051302] Call Trace:
> [ 919.053738] [<ffffffe000930d92>] __schedule+0x194/0x4de
> [ 982.035783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
> [ 982.040923] rcu: 0-...0: (0 ticks this GP)
> idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=113325
> [ 982.050294] (detected by 1, t=241580 jiffies, g=1561, q=3509)
> [ 982.056108] Task dump for CPU 0:
> [ 982.059321] kworker/0:1 R running task 0 30 2 0x00000008
> [ 982.066359] Workqueue: events set_brightness_delayed
> [ 982.071302] Call Trace:
> [ 982.073739] [<ffffffe000930d92>] __schedule+0x194/0x4de
> [..]
>
> Fixes: bb0fed1c60cc ("irqchip/sifive-plic: Switch to fasteoi flow")
> Signed-off-by: Greentime Hu <greentime.hu@xxxxxxxxxx>
> ---
> drivers/irqchip/irq-sifive-plic.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index eaa3e9fe54e9..4cc8a2657a6d 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -137,6 +137,7 @@ static int plic_set_affinity(struct irq_data *d,
> const struct cpumask *mask_val, bool force)
> {
> unsigned int cpu;
> + bool enable;
> struct cpumask amask;
> struct plic_priv *priv = irq_get_chip_data(d->irq);
>
> @@ -150,8 +151,10 @@ static int plic_set_affinity(struct irq_data *d,
> if (cpu >= nr_cpu_ids)
> return -EINVAL;
>
> + enable = !irqd_irq_disabled(d);
> plic_irq_toggle(&priv->lmask, d, 0);
> - plic_irq_toggle(cpumask_of(cpu), d, 1);
> + /* Keep its original setting. */
> + plic_irq_toggle(cpumask_of(cpu), d, enable);
>
> irq_data_update_effective_affinity(d, cpumask_of(cpu));
>
> --
> 2.28.0
>
>
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Good catch. Your fix looks good to me.

Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

Regards,
Anup