Messages in this thread | | | Date | Tue, 16 Mar 2021 06:57:05 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH v1 3/5] dt-bindings: arm: Add cpu-idle-states to Tegra194 CPU nodes |
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On Fri, Mar 12, 2021 at 02:27:30PM -0800, Sowjanya Komatineni wrote: > Hi Sudeep, > > To make our driver PSCI compliant below are few updates to be done > > 1. Standardize passing residency time run-time thru PSCI to ATF. >
Yes that was my initial understanding, but your previous response was confusing. I should have read this first.
> From PSCI specification I only see PSCI_STAT_RESIDENCY and > PSCI_STAT_COUNT optional functions for PSCI1.0/PSCI1.1 >
Indeed, we don't have any support to pass run-time residency hints in PSCI today.
> Can you please help add right people to explore on possible ways to add > PSCI function for passing corresponding state residency time to ATF? >
Before we jump to implementation in TF-A we need to get agreement to get this added to the specification to support in OSPM/Linux. TF-A is just one implementation of PSCI and may not be only one.
Formally you can raise any specification related queries to https://developer.arm.com/support or support@arm.com. I will ask the author of PSCI specification internally to take a look at this thread and chime in if they can.
> 2. Tegra CPU Idle support definitely need to pass deepest cluster state and > threshold to MCE firmware from DT and looks like we can move this > implementation to ATF >
Yes, I just asked the same question as response to your earlier email. Thanks for confirming that it can be moved out of OSPM/Linux and DT
> With both of the above implementation changes Tegra194 driver will be > PSCI compliant. >
We still need to get agreement on the specification front 😉.
-- Regards, Sudeep
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