Messages in this thread | | | From | Ulf Hansson <> | Date | Thu, 13 Dec 2018 15:53:22 +0100 | Subject | Re: [PATCH V3 3/6] OPP: Add dev_pm_opp_xlate_performance_state() helper |
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On Wed, 12 Dec 2018 at 11:57, Viresh Kumar <viresh.kumar@linaro.org> wrote: > > dev_pm_genpd_set_performance_state() needs to handle performance state > propagation going forward. Currently this routine only gets the required > performance state of the device's genpd as an argument, but it doesn't > know how to translate that to master genpd(s) of the device's genpd. > > Introduce a new helper dev_pm_opp_xlate_performance_state() which will > be used to translate from performance state of a device (or genpd > sub-domain) to another device (or master genpd). > > Normally the src_table (of genpd sub-domain) will have the > "required_opps" property set to point to one of the OPPs in the > dst_table (of master genpd), but in some cases the genpd and its master > have one to one mapping of performance states and so none of them have > the "required-opps" property set. Return the performance state of the > src_table as it is in such cases. > > Tested-by: Rajendra Nayak <rnayak@codeaurora.org> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/opp/core.c | 59 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/pm_opp.h | 7 +++++ > 2 files changed, 66 insertions(+) > > diff --git a/drivers/opp/core.c b/drivers/opp/core.c > index 98e60f0ed8b0..386095e2f4f7 100644 > --- a/drivers/opp/core.c > +++ b/drivers/opp/core.c > @@ -1713,6 +1713,65 @@ void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table, > dev_err(virt_dev, "Failed to find required device entry\n"); > } > > +/** > + * dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for src_table. > + * @src_table: OPP table which has dst_table as one of its required OPP table. > + * @dst_table: Required OPP table of the src_table. > + * @pstate: Current performance state of the src_table. > + * > + * This Returns pstate of the OPP (present in @dst_table) pointed out by the > + * "required-opps" property of the OPP (present in @src_table) which has > + * performance state set to @pstate. > + * > + * Return: Positive performance state on success, otherwise 0 on errors.
To simplify for callers, I would rather not have the return code 0 being treated as an error. Instead I would prefer 0 to mean that the state shall be set to zero (which means it should be perfectly fine to also give 0 as inparam for pstate)
For errors, I think it's better to return regular negative error codes, as it's standard and more flexible.
Kind regards Uffe
> + */ > +unsigned int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, > + struct opp_table *dst_table, > + unsigned int pstate) > +{ > + struct dev_pm_opp *opp; > + unsigned int dest_pstate = 0; > + int i; > + > + /* > + * Normally the src_table will have the "required_opps" property set to > + * point to one of the OPPs in the dst_table, but in some cases the > + * genpd and its master have one to one mapping of performance states > + * and so none of them have the "required-opps" property set. Return the > + * pstate of the src_table as it is in such cases. > + */ > + if (!src_table->required_opp_count) > + return pstate; > + > + for (i = 0; i < src_table->required_opp_count; i++) { > + if (src_table->required_opp_tables[i]->np == dst_table->np) > + break; > + } > + > + if (unlikely(i == src_table->required_opp_count)) { > + pr_err("%s: Couldn't find matching OPP table (%p: %p)\n", > + __func__, src_table, dst_table); > + return 0; > + } > + > + mutex_lock(&src_table->lock); > + > + list_for_each_entry(opp, &src_table->opp_list, node) { > + if (opp->pstate == pstate) { > + dest_pstate = opp->required_opps[i]->pstate; > + goto unlock; > + } > + } > + > + pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, src_table, > + dst_table); > + > +unlock: > + mutex_unlock(&src_table->lock); > + > + return dest_pstate; > +} > + > /** > * dev_pm_opp_add() - Add an OPP table from a table definitions > * @dev: device for which we do this operation > diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h > index 2b2c3fd985ab..5a64a81a1789 100644 > --- a/include/linux/pm_opp.h > +++ b/include/linux/pm_opp.h > @@ -128,6 +128,7 @@ struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev, int (*s > void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table); > struct opp_table *dev_pm_opp_set_genpd_virt_dev(struct device *dev, struct device *virt_dev, int index); > void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table, struct device *virt_dev); > +unsigned int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate); > int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq); > int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, const struct cpumask *cpumask); > int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask); > @@ -280,6 +281,12 @@ static inline struct opp_table *dev_pm_opp_set_genpd_virt_dev(struct device *dev > } > > static inline void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table, struct device *virt_dev) {} > + > +static inline unsigned int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate) > +{ > + return 0; > +} > + > static inline int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) > { > return -ENOTSUPP; > -- > 2.19.1.568.g152ad8e3369a >
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