From mboxrd@z Thu Jan 1 00:00:00 1970 From: lina.iyer@linaro.org (Lina Iyer) Date: Fri, 20 Nov 2015 09:28:35 -0700 Subject: [PATCH RFC 16/27] ARM: cpuidle: Record the next wakeup event of the CPU In-Reply-To: <7hwptdsgto.fsf@deeprootsystems.com> References: <1447799871-56374-1-git-send-email-lina.iyer@linaro.org> <1447799871-56374-17-git-send-email-lina.iyer@linaro.org> <7hwptdsgto.fsf@deeprootsystems.com> Message-ID: <20151120162835.GC30342@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Nov 19 2015 at 16:35 -0700, Kevin Hilman wrote: >Lina Iyer writes: > >> Reading the next wakeup of the CPU can only be realiably done only from >> that CPU. In the idle enter path record the next wake up of the CPU. The >> information is useful to determine the sleep time left for the CPU. >> >> Signed-off-by: Lina Iyer >> --- >> drivers/cpuidle/cpuidle-arm.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c >> index 8e72a23..b3133ef 100644 >> --- a/drivers/cpuidle/cpuidle-arm.c >> +++ b/drivers/cpuidle/cpuidle-arm.c >> @@ -18,9 +18,11 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> +#include >> >> #include >> >> @@ -49,7 +51,9 @@ static int arm_enter_idle_state(struct cpuidle_device *dev, >> ret = cpu_pm_enter(); >> if (!ret) { >> struct device *cpu_dev = get_cpu_device(dev->cpu); >> + struct generic_pm_domain_data *gpd = dev_gpd_data(cpu_dev); >> >> + gpd->td.next_wakeup = tick_nohz_get_next_wakeup(); >> RCU_NONIDLE(pm_runtime_put_sync_suspend(cpu_dev)); > >Maybe set this back to zero atomicaly, after wakeup? > >Checking for non-zero that might be another way for the domain goveror that there >haven't been any CPU wakeups since the CPUs have gone idle. > I set it to 0 below. The reference counting by the GET_PUT tells the domain if a device is suspended. I see that as a redudant information. May be I am not getting your point. -- Lina >Kevin