Messages in this thread | | | Date | Tue, 6 Aug 2019 17:34:11 +0100 | From | Lorenzo Pieralisi <> | Subject | Re: [PATCH 4/6] ARM: psci: cpuidle: Introduce PSCI CPUidle driver |
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On Tue, Aug 06, 2019 at 05:10:33PM +0100, Sudeep Holla wrote: > On Mon, Jul 22, 2019 at 04:37:43PM +0100, Lorenzo Pieralisi wrote: > > PSCI firmware is the standard power management control for > > all ARM64 based platforms and it is also deployed on some > > ARM 32 bit platforms to date. > > > > Idle state entry in PSCI is currently achieved by calling > > arm_cpuidle_init() and arm_cpuidle_suspend() in a generic > > idle driver, which in turn relies on ARM/ARM64 CPUidle back-end > > to relay the call into PSCI firmware if PSCI is the boot method. > > > > Given that PSCI is the standard idle entry method on ARM64 systems > > (which means that no other CPUidle driver are expected on ARM64 > > platforms - so PSCI is already a generic idle driver), in order to > > simplify idle entry and code maintenance, it makes sense to have a PSCI > > specific idle driver so that idle code that it is currently living in > > drivers/firmware directory can be hoisted out of it and moved > > where it belongs, into a full-fledged PSCI driver, leaving PSCI code > > in drivers/firmware as a pure firmware interface, as it should be. > > > > Implement a PSCI CPUidle driver. By default it is a silent Kconfig entry > > which is left unselected, since it selection would clash with the > > generic ARM CPUidle driver that provides a PSCI based idle driver > > through the arm/arm64 arches back-ends CPU operations. > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Cc: Ulf Hansson <ulf.hansson@linaro.org> > > Cc: Sudeep Holla <sudeep.holla@arm.com> > > Once the error path issues pointed by Ulf are resolved, > > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> > > > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > > Cc: Mark Rutland <mark.rutland@arm.com> > > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > > --- > > MAINTAINERS | 8 ++ > > drivers/cpuidle/Kconfig.arm | 3 + > > drivers/cpuidle/Makefile | 1 + > > drivers/cpuidle/cpuidle-psci.c | 150 +++++++++++++++++++++++++++++++++ > > 4 files changed, 162 insertions(+) > > create mode 100644 drivers/cpuidle/cpuidle-psci.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 783569e3c4b4..c2bf8ce65e83 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -4286,6 +4286,14 @@ S: Supported > > F: drivers/cpuidle/cpuidle-exynos.c > > F: arch/arm/mach-exynos/pm.c > > > > +CPUIDLE DRIVER - ARM PSCI > > +M: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > +M: Sudeep Holla <sudeep.holla@arm.com> > > +L: linux-pm@vger.kernel.org > > +L: linux-arm-kernel@lists.infradead.org > > +S: Supported > > +F: drivers/cpuidle/cpuidle-psci.c > > + > > CPU IDLE TIME MANAGEMENT FRAMEWORK > > M: "Rafael J. Wysocki" <rjw@rjwysocki.net> > > M: Daniel Lezcano <daniel.lezcano@linaro.org> > > diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm > > index 48cb3d4bb7d1..929b57424ea4 100644 > > --- a/drivers/cpuidle/Kconfig.arm > > +++ b/drivers/cpuidle/Kconfig.arm > > @@ -13,6 +13,9 @@ config ARM_CPUIDLE > > initialized by calling the CPU operations init idle hook > > provided by architecture code. > > > > +config ARM_PSCI_CPUIDLE > > + bool > > + > > [nit] I understand the intention to keep it hidden, but can't we have > the dependency and selection of other config as part of this patch to > make it more complete ?
Yes we can, it makes sense.
Thanks, Lorenzo
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