Re: [PATCH v3 2/2] clocksource/drivers/timer-riscv: Stop stimecmp when cpu hotplug

[Daniel Lezcano]

On 28/10/2024 04:39, Nick Hu wrote:
> Stop the timer when the cpu is going to be offline otherwise the
> timer interrupt may be pending while performing power-down.
>
> Suggested-by: Anup Patel <anup@xxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/lkml/20240829033904.477200-3-nick.hu@xxxxxxxxxx/T/#u
> Signed-off-by: Nick Hu <nick.hu@xxxxxxxxxx>
> Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
> ---
>   drivers/clocksource/timer-riscv.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
> index 48ce50c5f5e6..166dee14e46b 100644
> --- a/drivers/clocksource/timer-riscv.c
> +++ b/drivers/clocksource/timer-riscv.c
> @@ -127,6 +127,12 @@ static int riscv_timer_starting_cpu(unsigned int cpu)
>   static int riscv_timer_dying_cpu(unsigned int cpu)
>   {
>   	disable_percpu_irq(riscv_clock_event_irq);
> +	/*
> +	 * Stop the timer when the cpu is going to be offline otherwise
> +	 * the timer interrupt may be pending while performing power-down.
> +	 */
> +	riscv_clock_event_stop();
> +
>   	return 0;
>   }

Should it not be the opposite?

First stop the clock which clears the interrupt and then disable the irq?





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