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SubjectRe: [PATCH] opp: Return genpd virtual devices from dev_pm_opp_attach_genpd()
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On 7/17/2019 11:17 AM, Viresh Kumar wrote:
> On 11-07-19, 15:09, Rajendra Nayak wrote:
>> Sorry for the delay
>
> Same here :)
>
>> I seem to have completely missed this patch.
>> I just gave this a try and here are some observations,
>>
>> I have a case where I have one device with 2 power domains, one of them
>> is scale-able (supports perf state) and the other one supports only being
>> turned on and off.
>>
>> 1. In the driver I now need to use dev_pm_domain_attach_by_name/id to attach the
>> power domain which supports only on/off and then use dev_pm_opp_attach_genpd()
>> for the one which supports perf states.
>>
>> 2. My OPP table has only 1 required_opps, so the required_opp_count for the OPP table is 1.
>> Now if my device tree has my scale-able powerdomain at index 1 (it works if its at index 0)
>> then I end up with this error
>>
>> [ 2.858628] ufshcd-qcom 1d84000.ufshc: Index can't be greater than required-opp-count - 1, rpmh_pd (1 : 1)
>>
>> so it looks like a lot of the OPP core today just assumes that if a device has multiple power domains,
>> all of them are scale-able which isn't necessarily true.
>
> I don't think a lot of OPP core has these problems, but maybe only
> this place. I was taking care of this since the beginning just forgot
> it now.
>
> What about this over this commit:

Yes, this does seem to fix my concern mentioned in 2. above.

>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index d76ead4eff4c..1f11f8c92337 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1789,13 +1789,16 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
> *
> * This helper needs to be called once with a list of all genpd to attach.
> * Otherwise the original device structure will be used instead by the OPP core.
> + *
> + * The order of entries in the names array must match the order in which
> + * "required-opps" are added in DT.
> */
> struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
> const char **names, struct device ***virt_devs)
> {
> struct opp_table *opp_table;
> struct device *virt_dev;
> - int index, ret = -EINVAL;
> + int index = 0, ret = -EINVAL;
> const char **name = names;
>
> opp_table = dev_pm_opp_get_opp_table(dev);
> @@ -1821,14 +1824,6 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
> goto unlock;
>
> while (*name) {
> - index = of_property_match_string(dev->of_node,
> - "power-domain-names", *name);
> - if (index < 0) {
> - dev_err(dev, "Failed to find power domain: %s (%d)\n",
> - *name, index);
> - goto err;
> - }
> -
> if (index >= opp_table->required_opp_count) {
> dev_err(dev, "Index can't be greater than required-opp-count - 1, %s (%d : %d)\n",
> *name, opp_table->required_opp_count, index);
> @@ -1849,6 +1844,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
> }
>
> opp_table->genpd_virt_devs[index] = virt_dev;
> + index++;
> name++;
> }
>
>

--
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