From: Sudeep Holla <sudeep.holla@arm.com>
To: Maulik Shah <mkshah@codeaurora.org>
Cc: swboyd@chromium.org, agross@kernel.org, david.brown@linaro.org,
Lorenzo.Pieralisi@arm.com, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, bjorn.andersson@linaro.org,
evgreen@chromium.org, dianders@chromium.org,
rnayak@codeaurora.org, ilina@codeaurora.org,
lsrao@codeaurora.org, ulf.hansson@linaro.org, rjw@rjwysocki.net,
Sudeep Holla <sudeep.holla@arm.com>
Subject: Re: [PATCH v3 5/7] drivers: firmware: psci: Add hierarchical domain idle states converter
Date: Tue, 4 Feb 2020 15:21:32 +0000 [thread overview]
Message-ID: <20200204152132.GA44858@bogus> (raw)
In-Reply-To: <0d7f7ade-3a1e-5428-d851-f1a886f58712@codeaurora.org>
On Tue, Feb 04, 2020 at 10:22:42AM +0530, Maulik Shah wrote:
>
> On 2/3/2020 10:38 PM, Sudeep Holla wrote:
> > On Mon, Feb 03, 2020 at 07:05:38PM +0530, Maulik Shah wrote:
> > > From: Ulf Hansson <ulf.hansson@linaro.org>
> > >
> > > If the hierarchical CPU topology is used, but the OS initiated mode isn't
> > > supported, we need to rely solely on the regular cpuidle framework to
> > > manage the idle state selection, rather than using genpd and its
> > > governor.
> > >
> > > For this reason, introduce a new PSCI DT helper function,
> > > psci_dt_pm_domains_parse_states(), which parses and converts the
> > > hierarchically described domain idle states from DT, into regular flattened
> > > cpuidle states. The converted states are added to the existing cpuidle
> > > driver's array of idle states, which make them available for cpuidle.
> > >
> > And what's the main motivation for this if OSI is not supported in the
> > firmware ?
>
> Hi Sudeep,
>
> Main motivation is to do last-man activities before the CPU cluster can
> enter a deep idle state.
>
Details on those last-man activities will help the discussion. Basically
I am wondering what they are and why they need to done in OSPM ?
> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > > [applied to new path, resolved conflicts]
> > > Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
> > > ---
> > > drivers/cpuidle/cpuidle-psci-domain.c | 137 +++++++++++++++++++++++++++++-----
> > > drivers/cpuidle/cpuidle-psci.c | 41 +++++-----
> > > drivers/cpuidle/cpuidle-psci.h | 11 +++
> > > 3 files changed, 153 insertions(+), 36 deletions(-)
> > >
> > > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
> > > index 423f03b..3c417f7 100644
> > > --- a/drivers/cpuidle/cpuidle-psci-domain.c
> > > +++ b/drivers/cpuidle/cpuidle-psci-domain.c
> > > @@ -26,13 +26,17 @@ struct psci_pd_provider {
> > > };
> > >
> > > static LIST_HEAD(psci_pd_providers);
> > > -static bool osi_mode_enabled __initdata;
> > > +static bool osi_mode_enabled;
> > >
> > > static int psci_pd_power_off(struct generic_pm_domain *pd)
> > > {
> > > struct genpd_power_state *state = &pd->states[pd->state_idx];
> > > u32 *pd_state;
> > >
> > > + /* If we have failed to enable OSI mode, then abort power off. */
> > > + if ((psci_has_osi_support()) && !osi_mode_enabled)
> > > + return -EBUSY;
> > > +
> > Why is this needed ? IIUC we don't create genpd domains if OSI is not
> > enabled.
>
> we do create genpd domains, for cpu domains, we just abort power off here
> since idle states are converted into regular flattened mode.
>
OK, IIRC the OSI patches from Ulf didn't add the genpd or rather removed
them in case of any failure to enable OSI. Has that been changed ? If so,
why ?
> however genpd poweroff will be used by parent domain (rsc in this case)
> which is kept in hireachy in DTSI with cluster domain to do last man
> activities.
>
I am bit confused here. Either we do OSI or PC and what you are describing
sounds like a mix-n-match to me and I am totally against it.
--
Regards,
Sudeep
next prev parent reply other threads:[~2020-02-04 15:21 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-03 13:35 [PATCH v3 0/7] Add RSC power domain support Maulik Shah
2020-02-03 13:35 ` [PATCH v3 1/7] drivers: qcom: rpmh: fix macro to accept NULL argument Maulik Shah
2020-02-03 13:35 ` [PATCH v3 2/7] drivers: qcom: rpmh: remove rpmh_flush export Maulik Shah
2020-02-03 13:35 ` [PATCH v3 3/7] dt-bindings: soc: qcom: Add RSC power domain specifier Maulik Shah
2020-02-03 13:35 ` [PATCH v3 4/7] drivers: qcom: rpmh-rsc: Add RSC power domain support Maulik Shah
2020-02-03 13:35 ` [PATCH v3 5/7] drivers: firmware: psci: Add hierarchical domain idle states converter Maulik Shah
2020-02-03 17:08 ` Sudeep Holla
2020-02-04 4:52 ` Maulik Shah
2020-02-04 15:21 ` Sudeep Holla [this message]
2020-02-05 12:23 ` Maulik Shah
2020-02-05 14:06 ` Sudeep Holla
2020-02-05 15:55 ` Ulf Hansson
2020-02-05 16:18 ` Sudeep Holla
2020-02-06 8:45 ` Ulf Hansson
2020-02-06 20:45 ` Lina Iyer
2020-02-07 11:20 ` Sudeep Holla
2020-02-07 12:32 ` Ulf Hansson
2020-02-07 14:48 ` Lorenzo Pieralisi
2020-02-07 15:52 ` Ulf Hansson
2020-02-07 16:15 ` Sudeep Holla
2020-02-08 10:25 ` Ulf Hansson
2020-02-10 10:31 ` Sudeep Holla
2020-02-07 16:05 ` Sudeep Holla
2020-02-06 21:11 ` Bjorn Andersson
2020-02-07 11:25 ` Sudeep Holla
2020-02-03 13:35 ` [PATCH v3 6/7] arm64: dts: qcom: sc7180: Add cpuidle low power states Maulik Shah
2020-02-04 23:15 ` Matthias Kaehlcke
2020-02-05 12:07 ` Maulik Shah
2020-02-03 13:35 ` [PATCH v3 7/7] arm64: dts: qcom: sc7180: Convert to the hierarchical CPU topology layout Maulik Shah
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