| Message ID | 1390299016-14105-6-git-send-email-acourbot@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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?
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?
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?
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.
diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c index e0b87300243d..c42fd41065d2 100644 --- a/arch/arm/mach-tegra/cpuidle-tegra114.c +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c @@ -19,6 +19,7 @@ #include <linux/cpuidle.h> #include <linux/cpu_pm.h> #include <linux/clockchips.h> +#include <asm/firmware.h> #include <asm/cpuidle.h> #include <asm/suspend.h> @@ -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);
Invoke the do_idle() firmware call before suspending a CPU so that the underlying firmware (if any) can take necessary action. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> --- arch/arm/mach-tegra/cpuidle-tegra114.c | 3 +++ 1 file changed, 3 insertions(+)