Re: [PATCH 1/2] time : pass broadcast device parameter

From: Viresh Kumar
Date: Tue Feb 26 2013 - 07:14:35 EST


On 26 February 2013 17:01, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote:
> Oh, by the way, could send me the patch to set the flag to the timer
> device ? I will include it to the patchset.

Sure. Find it attached too as gmail may break it.

commit 14422c760bb5b2485867f3efb7842d296081ad86
Author: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Date: Fri Feb 22 12:42:39 2013 +0530

ARM/timer-sp: Set dynamic irq affinity

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@xxxxxxxxxx>
---
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,

Attachment: 0001-ARM-timer-sp-Set-dynamic-irq-affinity.patch
Description: Binary data