Messages in this thread | | | Date | Thu, 6 Feb 2014 11:28:24 +0900 | From | Alexandre Courbot <> | Subject | Re: [PATCH 5/5] ARM: tegra: cpuidle: use firmware call for power down |
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On 02/06/2014 01:28 AM, Stephen Warren wrote: > On 01/23/2014 12:39 AM, Alexandre Courbot wrote: >> On Thu, Jan 23, 2014 at 5:45 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: >>> On 01/21/2014 03:10 AM, Alexandre Courbot wrote: >>>> Invoke the do_idle() firmware call before suspending a CPU so that the >>>> underlying firmware (if any) can take necessary action. >>> >>>> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c >>> >>>> @@ -45,6 +46,8 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev, >>>> >>>> clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); >>>> >>>> + call_firmware_op(do_idle); >>>> + >>>> cpu_suspend(0, tegra30_sleep_cpu_secondary_finish); >>>> >>>> clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); >>> >>> Don't you need to have the kernel also *not* do something when entering >>> idle; doesn't the FW op replace some of the register writes that the >>> kernel would otherwise be doing? >> >> It seems like the operation is actually to inform the firmware that we >> are going to suspend the CPU. Downstream kernel also uses it that way. >> But you are right in that we should expect do_idle() to actually >> perform the suspend operation. Maybe a prepare_idle() operation should >> be added to the firmware interface for this purpose? > > That sounds like a reasonable change. Is it easy to plumb in?
I think so. Will post a v2 of this soon.
Thanks, Alex.
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