On Fri, 9 Jul 2021 at 13:46, Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> wrote: > > On Fri, 9 Jul 2021 at 12:33, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > > > On Fri, 9 Jul 2021 at 06:32, Dmitry Baryshkov > > <dmitry.baryshkov@xxxxxxxxxx> wrote: > > > > > > On sm8250 dispcc and videocc registers are powered up by the MMCX power > > > domain. Currently we used a regulator to enable this domain on demand, > > > however this has some consequences, as genpd code is not reentrant. > > > > > > Teach Qualcomm clock controller code about setting up power domains and > > > using them for gdsc control. > > > > > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> > > > > [...] > > > > > diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c > > > index 51ed640e527b..9401d01533c8 100644 > > > --- a/drivers/clk/qcom/gdsc.c > > > +++ b/drivers/clk/qcom/gdsc.c > > > @@ -427,6 +427,7 @@ int gdsc_register(struct gdsc_desc *desc, > > > continue; > > > scs[i]->regmap = regmap; > > > scs[i]->rcdev = rcdev; > > > + scs[i]->pd.dev.parent = desc->dev; > > > ret = gdsc_init(scs[i]); > > > if (ret) > > > return ret; > > > @@ -439,6 +440,8 @@ int gdsc_register(struct gdsc_desc *desc, > > > continue; > > > if (scs[i]->parent) > > > pm_genpd_add_subdomain(scs[i]->parent, &scs[i]->pd); > > > + else if (!IS_ERR_OR_NULL(dev->pm_domain)) > > > > So dev_pm_domain_attach() (which calls genpd_dev_pm_attach() is being > > called for gdsc platform device from the platform bus', to try to > > attach the device to its corresponding PM domain. > > > > Looking a bit closer to genpd_dev_pm_attach(), I realize that we > > shouldn't really try to attach a device to its PM domain, when its OF > > node (dev->of_node) contains a "#power-domain-cells" specifier. This > > is because it indicates that the device belongs to a genpd provider > > itself. In this case, a "power-domains" specifier tells that it has a > > parent domain. > > > > I will post a patch that fixes this asap. > > I think there is nothing to fix here. The dispcc/videocc drivers > provide clocks in addition to the gdsc power domain. And provided > clocks would definitely benefit from having the dispcc device being > attached to the power domain which governs clock registers (MMCX in > our case). Thus I think it is perfectly valid to have: > > rpmhpd device: > - provides MMCX domain. > > dispcc device: > - is attached to the MMCX domain, We don't need this, it's redundant and weird to me. Also I am kind of worried that you will hit another new path in genpd, causing locking issues etc, as it has not been designed to work like this (a provider device and a child domain sharing the same "parent"). > - provides MDSS_GDSC It's perfectly fine that dispcc acts as a genpd provider. In this case, the corresponding PM domain should be assigned as a child for the parent MMCX domain. That should make this work, I think. > - provides clocks That sounds reasonable as well. > > > > > > + pm_genpd_add_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd); > > > } > > > > > > return of_genpd_add_provider_onecell(dev->of_node, data); > > > @@ -457,6 +460,8 @@ void gdsc_unregister(struct gdsc_desc *desc) > > > continue; > > > if (scs[i]->parent) > > > pm_genpd_remove_subdomain(scs[i]->parent, &scs[i]->pd); > > > + else if (!IS_ERR_OR_NULL(dev->pm_domain)) > > > > Ditto. > > > > > + pm_genpd_remove_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd); > > > } > > > of_genpd_del_provider(dev->of_node); > > > } > > > -- > > > 2.30.2 > > > > > Kind regards Uffe
