On Wed, Nov 13, 2024 at 01:57:23PM +0100, Lorenzo Pieralisi wrote: > On Mon, Oct 28, 2024 at 03:22:59PM +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. > > > > This works exactly like SYSTEM_SUSPEND. The PSCI spec describes that > > call as optional (and only introduced in PSCIv1.0), so not all > > platforms expose it. > > > > Marking a DT-described "domain-idle-state" as such isn't currently > > well accounted for in the PSCI idle topology infrastructure: the > > cpuidle and genpd framework are deeply intertwined, and trying to > > separate them would cause more havoc than good. > > I don't understand what you mean here please elaborate. > > The part of the story I understand is that you have a system (well, > firmware for an extended set of systems) that does not implement > SYSTEM_SUSPEND but can reach a S2R like system state through the > CPU_SUSPEND call. Firmware works in OS-initiated mode, idle-states > should allow you to define idle states that allow the system to > enter the S2R state through CPUidle. > > Please explain to me what's missing. > > > Instead, allow the specifying of a single CPU_SUSPEND sleep param > > under the /psci node that shall be treated exactly like SYSTEM_SUSPEND > > from Linux's POV. As a bonus, this way we also don't have to fight > > with the genpd idle governor to avoid taking the S3-like state into > > consideration. > > That's not acceptable. I want to understand what's preventing this > system to enter that state through suspend2idle and the mainline code. > > > Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx> > > --- > > drivers/firmware/psci/psci.c | 36 +++++++++++++++++++++++++++++++----- > > 1 file changed, 31 insertions(+), 5 deletions(-) > > NACK > +1, will wait for the response here before adding any more questions that may lead to more confusion or discussion churn. -- Regards, Sudeep
