Messages in this thread | | | From | Dmitry Baryshkov <> | Date | Thu, 1 Jul 2021 14:01:10 +0300 | Subject | Re: [PATCH 2/2] PM: domain: use per-genpd lockdep class |
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On Thu, 1 Jul 2021 at 13:07, Ulf Hansson <ulf.hansson@linaro.org> wrote: > > On Tue, 29 Jun 2021 at 17:09, Bjorn Andersson > <bjorn.andersson@linaro.org> wrote: > > > > On Mon 28 Jun 14:55 CDT 2021, Dmitry Baryshkov wrote: > > > > > Hi, > > > > > > On 17/06/2021 12:07, Ulf Hansson wrote: > > > > + Rajendra > > > > > > > > On Tue, 15 Jun 2021 at 17:55, Bjorn Andersson > > > > <bjorn.andersson@linaro.org> wrote: > > [..] > > > > > But I am unable to find a way for the gdsc driver to get hold of the > > > > > struct generic_pm_domain of the resources exposed by the rpmhpd driver. > > > > > > > > You don't need a handle to the struct generic_pm_domain, to assign a > > > > parent/child domain. Instead you can use of_genpd_add_subdomain(), > > > > which takes two "struct of_phandle_args*" corresponding to the > > > > parent/child device nodes of the genpd providers and then let genpd > > > > internally do the look up. > > > > > [..] > > > > > > I think I'd need this function anyway for the gdsc code. During gdsc_init() > > > we check gdsc status and this requires register access (and thus powering on > > > the parent domain) before the gdsc is registered itself as a power domain. > > > > > > > But this is a register access in the dispcc block, which is the context > > that our gdsc_init() operates. So describing that MMCX is the > > power-domain for dispcc should ensure that the power-domain is enabled. > > Right. > > As a note, when we assign a child domain to a parent domain, via > of_genpd_add_subdomain() for example - and the child domain has been > powered on, this requires the parent domain to be turned on as well.
Most probably we should also teach genpd code to call pm_runtime functions on respective devices when the genpd is powered on or off. For now I had to do this manually.
> > > > > We do however need to make sure that dispcc doesn't hog its > > power-domain, and that any register accesses in runtime is done with the > > parenting power-domain enabled. E.g. the clock framework wraps all > > operations in pm_runtime_get/put(), but I don't see anything in the > > gnepd code for this. > > > > > > And for gcc I'm worried that we might have some GDSCs that are parented > > by CX and some by MX, but I do still think that the register accesses > > are only related to one of these. > > > > But this seems like a continuation of the special case in dispcc, so I > > think we should be able to focus on getting that right before we attempt > > the general case (and I don't know if we have a need for this today). > > > > Regards, > > Bjorn > > Unfortunately, I didn't understand all the above things. > > In any case, please tell me if there is anything else that blocks you > from moving forward with the power domain conversion? I am happy to > help.
Patch series was submitted: https://lore.kernel.org/linux-arm-msm/20210630133149.3204290-1-dmitry.baryshkov@linaro.org/
-- With best wishes Dmitry
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