[PATCH 4/4][V2] ARM: timer-sp: Set dynamic irq affinity

Daniel Lezcano daniel.lezcano at linaro.org
Fri Mar 8 10:28:55 EST 2013


On 03/02/2013 11:10 AM, Daniel Lezcano wrote:
> From: Viresh Kumar <viresh.kumar at linaro.org>
> 
> When a cpu goes to a deep idle state where its local timer is shutdown, it
> notifies the time frame work to use the broadcast timer instead.
> 
> Unfortunately, the broadcast device could wake up any CPU, including an idle one
> which is not concerned by the wake up at all.
> 
> This implies, in the worst case, an idle CPU will wake up to send an IPI to
> another idle cpu.
> 
> This patch fixes this for ARM platforms using timer-sp, by setting
> CLOCK_EVT_FEAT_DYNIRQ feature.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar at linaro.org>
> Signed-off-by: Daniel Lezcano <daniel.lezcano at linaro.org>
> ---

Hi Russell,

I asked Thomas if he could take this patch in its tree but it falls
under your umbrella. Thomas agreed to take it if you ack this patch.

Is this patch acceptable for you ?

Thanks in advance
  -- Daniel


>  arch/arm/common/timer-sp.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/common/timer-sp.c b/arch/arm/common/timer-sp.c
> index 9d2d3ba..ae3c0f9 100644
> --- a/arch/arm/common/timer-sp.c
> +++ b/arch/arm/common/timer-sp.c
> @@ -158,7 +158,8 @@ static int sp804_set_next_event(unsigned long next,
>  }
>  
>  static struct clock_event_device sp804_clockevent = {
> -	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
> +	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
> +		CLOCK_EVT_FEAT_DYNIRQ,
>  	.set_mode	= sp804_set_mode,
>  	.set_next_event	= sp804_set_next_event,
>  	.rating		= 300,
> 


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