Re: [PATCH v2 29/48] soc/tegra: pmc: Link domains to the parent Core domain

[Dmitry Osipenko]

12.01.2021 16:30, Ulf Hansson пишет:
> - trimmed cc-list
> 
> On Thu, 17 Dec 2020 at 19:07, Dmitry Osipenko <digetx@xxxxxxxxx> wrote:
>>
>> The Core domain is a parent of PMC power domains, hence PMC domains
>> should be set up as a sub-domains of the parent (Core) domain if
>> "power-domains" phandle presents in a device-tree node of PMC domain.
>>
>> This allows to propagate GENPD performance changes to the parent Core
>> domain if performance change is applied to PMC domain.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>> ---
>>  drivers/soc/tegra/pmc.c | 19 +++++++++++++++++++
>>  1 file changed, 19 insertions(+)
>>
>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>> index 4f96dc7745c4..1a659d1c06d7 100644
>> --- a/drivers/soc/tegra/pmc.c
>> +++ b/drivers/soc/tegra/pmc.c
>> @@ -1236,6 +1236,7 @@ static int tegra_powergate_add(struct tegra_pmc *pmc, struct device_node *np)
>>  static int tegra_powergate_init(struct tegra_pmc *pmc,
>>                                 struct device_node *parent)
>>  {
>> +       struct of_phandle_args child_args, parent_args;
>>         struct device_node *np, *child;
>>         int err = 0;
>>
>> @@ -1249,6 +1250,24 @@ static int tegra_powergate_init(struct tegra_pmc *pmc,
>>                         of_node_put(child);
>>                         break;
>>                 }
>> +
>> +               if (of_parse_phandle_with_args(child, "power-domains",
>> +                                              "#power-domain-cells",
>> +                                              0, &parent_args))
>> +                       continue;
>> +
>> +               child_args.np = child;
>> +               child_args.args_count = 0;
>> +
>> +               err = of_genpd_add_subdomain(&parent_args, &child_args);
>> +               of_node_put(parent_args.np);
>> +               if (err) {
>> +                       if (err == -ENOENT)
>> +                               err = -EPROBE_DEFER;
> 
> Okay. So this special error treatment is needed because
> of_genpd_add_subdomain may return -ENOENT, in case the providers for
> the parent-domain and child-domain haven't been registered yet.
> 
> I suggest we move this into of_genpd_add_subdomain() instead, thus
> letting it return -EPROBE_DEFER when there are parent/child nodes
> specified in DT, but the providers are lacking.

Alright