On Fri, Dec 20, 2024 at 01:54:45PM +0100, Konrad Dybcio wrote: > On 20.12.2024 12:27 PM, Sudeep Holla wrote: > > On Thu, Dec 19, 2024 at 08:43:27PM +0100, Konrad Dybcio wrote: > >> On 6.12.2024 11:21 AM, Sudeep Holla wrote: > >>> On Mon, Oct 28, 2024 at 03:22:57PM +0100, Konrad Dybcio wrote: > >>>> From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx> > >>>> > >>>> Certain firmware implementations (such as the ones found on Qualcomm > >>>> SoCs between roughly 2015 and 2023) expose an S3-like S2RAM state > >>>> through the CPU_SUSPEND call, as opposed to exposing PSCIv1.0's > >>>> optional PSCI_SYSTEM_SUSPEND. > >>>> > >>> > >>> If so, can you elaborate why s2idle doesn't work as an alternative to what > >>> you are hacking up here. > >> > >> Please see other branches of this thread > >> > >>> > >>>> This really doesn't work well with the model where we associate all > >>>> calls to CPU_SUSPEND with cpuidle. Allow specifying a single special > >>>> CPU_SUSPEND suspend parameter value that is to be treated just like > >>>> SYSTEM_SUSPEND from the OS's point of view. > >>>> > >>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx> > >>>> --- > >>>> Documentation/devicetree/bindings/arm/psci.yaml | 6 ++++++ > >>>> 1 file changed, 6 insertions(+) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml > >>>> index cbb012e217ab80c1ca88e611e7acc06c6d56fad0..a6901878697c8e1ec1cbfed62298ae3bc58f2501 100644 > >>>> --- a/Documentation/devicetree/bindings/arm/psci.yaml > >>>> +++ b/Documentation/devicetree/bindings/arm/psci.yaml > >>>> @@ -98,6 +98,12 @@ properties: > >>>> [1] Kernel documentation - ARM idle states bindings > >>>> Documentation/devicetree/bindings/cpu/idle-states.yaml > >>>> > >>>> + arm,psci-s2ram-param: > >>>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>>> + description: > >>>> + power_state parameter denoting the S2RAM/S3-like system suspend state > >>> > >>> Yet another NACK as this corresponds to PSCI SYSTEM_SUSPEND and as per > >>> specification it takes no such parameter. This is just misleading. > >>> > >> > >> Yeah PSCI_SYSTEM_SUSPEND takes care of this on platforms that expose it. > >> > > > > And those that don't advertise/expose don't get to use, simple. > > The spec says: > > "The call is equivalent to using the CPU_SUSPEND call for the > deepest possible platform powerdown state." > Please take a look at the preconditions for both the calls. They are different. -- Regards, Sudeep
