From mboxrd@z Thu Jan 1 00:00:00 1970 From: josephl@nvidia.com (Joseph Lo) Date: Thu, 13 Jun 2013 10:13:39 +0800 Subject: [PATCH V2 3/3] ARM: tegra114: cpuidle: add powered-down state In-Reply-To: <51B8B2C8.1090006@wwwdotorg.org> References: <1370342880-422-1-git-send-email-josephl@nvidia.com> <1370342880-422-4-git-send-email-josephl@nvidia.com> <51AE5EE3.3010607@linaro.org> <51B8B2C8.1090006@wwwdotorg.org> Message-ID: <1371089619.1681.21.camel@jlo-ubuntu-64.nvidia.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 2013-06-13 at 01:41 +0800, Stephen Warren wrote: > On 06/04/2013 03:40 PM, Daniel Lezcano wrote: > > On 06/04/2013 12:48 PM, Joseph Lo wrote: > >> This supports CPU core power down on each CPU when CPU idle. When CPU go > >> into this state, it saves it's context and needs a proper configuration > >> in flow controller to power gate the CPU when CPU runs into WFI > >> instruction. And the CPU also needs to set the IRQ as CPU power down idle > >> wake up event in flow controller. > >> > >> Signed-off-by: Joseph Lo > > > > I would like to understand why there is a WARN with the > > CPUIDLE_FLAG_TIMER_STOP flag set before queuing this patch and ensure it > > is not the tree hiding the forest. > > Joseph, are you planning to post an updated series or respond to resolve > Daniel's question? I need more time to investigate the detail about what caused the WARN when apply the flag. And what's the difference if we didn't enable CONFIG_CPU_IDLE_MULTIPLE_DRIVERS, then it only applies CLOCK_EVT_NOTIFY_BROADCAST_ON on CPU0. Why if I am moving the clockevent_notify of CLOCK_EVT_NOTIFY_BROADCAST_EXIT before "local_irq_enable" in the "cpuidle_enter_state" (drivers/cpuidle/cpuidle.c), then the warning message gone? Daniel, Because I need more time to figure it out, are you OK if I can post another patch to apply CPUIDLE_FLAG_TIMER_STOP flag for all Tegra CPU Idle drivers later? (Once we know what's the problem behind this) Stephen, I don't have an update of this series, if Daniel is OK if I can post another patch to apply TIMER_STOP flag for all Tegra idle drivers. Thanks, Joseph