On 31.05.2023 23:45, Doug Anderson wrote: > Hi, > > On Wed, May 31, 2023 at 7:26 AM Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote: >> >> On 31.05.2023 15:22, Konrad Dybcio wrote: >>> As pointed out in [1], the Linux implementation of RSC basically requires >>> (even if not explicitly) that we point it to a power domain which >>> represents the power state of the CPUs. In an effort to fulfill that >>> requirement, make it required in bindings and hook it up on all platforms >>> where I was able to do. This means all RPMh platforms, except >>> >>> - SC7180 >>> - SC7280 >>> - SA8775 >>> >>> As there wasn't an idle-states setup (which may be on purpose for CrOS >>> devices, certainly not for Windows SC7[12]80s) that I could validate. >>> (Doug, Bartosz, could you guys look into your respective platforms of >>> interest here?) >>> >>> This series also adds support for idle states on SM6350, as I was able >>> to add and test that. >> I noticed that 7280 is WIP: >> >> https://lore.kernel.org/lkml/20230424110933.3908-4-quic_mkshah@xxxxxxxxxxx/ > > Right. For sc7180 Chromebooks we don't use OSI (OS Initiated) mode but > instead use PC (Platform Coordinated) mode. As I understand it, that > means we take a different path through all this stuff. > > That being said, in the sc7280 thread you pointed at, Bjorn and Ulf > said that we could use the new device tree snippets for sc7280 even > before the ATF update. If I'm reading the thread correctly and the > same applies to sc7180: > > 1. New DT plus firmware that doesn't support OSI - OK > 2. New DT plus firmware that supports OSI - OK after code changes > 3. Old DT plus firmware that doesn't support OSI - OK > 4. Old DT plus firmware that supports OSI - Not OK > > For sc7180 Chromebooks we'll never have firmware that supports OSI. > That means that, assuming I'm understanding correctly, we actually > could move the DT to represent things the new way. Presumably this > would be important for sc7180 devices that originally shipped with > Windows (I think support for one of these is underway). It's even merged now! Yeah, AFAICT all you said makes sense I don't however know how you tell RSC driver that your platform is going to sleep when using PC mode.. KOnrad > > -Doug
