On Sun, 29 Aug 2021 at 17:54, Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> wrote: > > On Sun, 29 Aug 2021 at 06:51, Stephen Boyd <sboyd@xxxxxxxxxx> wrote: > > > > Quoting Dmitry Baryshkov (2021-08-26 14:56:23) > > > On 26/08/2021 21:31, Stephen Boyd wrote: > > > > Quoting Dmitry Baryshkov (2021-07-27 13:19:56) > > > >> On SM8250 both the display and video clock controllers are powered up by > > > >> the MMCX power domain. Handle this by linking clock controllers to the > > > >> proper power domain, and using runtime power management to enable and > > > >> disable the MMCX power domain. > > > >> > > > >> Dependencies: > > > >> - https://lore.kernel.org/linux-arm-msm/20210703005416.2668319-1-bjorn.andersson@xxxxxxxxxx/ > > > >> (pending) > > > > > > > > Does this patch series need to go through the qcom tree? Presumably the > > > > dependency is going through qcom -> arm-soc > > > > > > It looks like Bjorn did not apply his patches in the for-5.15 series, so > > > we'd have to wait anyway. Probably I should rebase these patches instead > > > on Rajendra's required-opps patch (which is going in this window). > > > > > > > Ok. Thanks. I'll drop it from my queue for now. > > Just for the reference. I've sent v7 of this patchset. After thinking > more about power domains relationship, I think we have a hole in the > abstraction here. Currently subdomains cause power domains to be > powered up, but do not dictate the performance level the parent domain > should be working in. That's not entirely true. In genpd_add_subdomain() we verify that if the child is powered on, the parent must already be powered on, otherwise we treat this a bad setup and return an error code. What seems to be missing though, is that if there is a performance state applied for the child domain, that should be propagated to the parent domain too. Right? > While this does not look like an issue for the > gdsc (and thus it can be easily solved by the Bjorn's patches, which > enforce rpmhpd to be powered on to 'at least lowest possible' > performance state, this might be not the case for the future links. I > think at some point the pd_add_subdomain() interface should be > extended with the ability to specify minimum required performance > state when the link becomes on. I guess that minimum performance state could be considered as a "required-opp" in the DT node for the power-domain provider, no? Another option would simply be to manage this solely in the platform/soc specific genpd provider. Would that work? > Until that time I have changed code to > enforce having clock controller in pm resume state when gdsc is > enabled, thus CC itself votes on parent's (rpmhpd) performance state. > > > -- > With best wishes > Dmitry Kind regards Uffe
