Messages in this thread |  | | Subject | Re: [PATCH v3 5/7] drivers: firmware: psci: Add hierarchical domain idle states converter | From | Maulik Shah <> | Date | Wed, 5 Feb 2020 17:53:00 +0530 |
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On 2/4/2020 8:51 PM, Sudeep Holla wrote: > 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 ?
Hi Sudeep,
there are cases like,
Last cpu going to deepest idle mode need to lower various resoruce requirements (for eg DDR freq).
This is done by calling rpmh_flush which send SLEEP values for various shared resources.
>>>> 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.
we still do PC based on sc7180. there is no OSI.
can you please check v4 series, i have cleaned this change by remove converter part.
Thanks,
Maulik
> > -- > Regards, > Sudeep
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