On 26 February 2016 at 16:48, Jon Hunter <jonathanh@xxxxxxxxxx> wrote: > To remove generic PM domains in a sane way, we need to remove them by > starting from the last PM domain added. The reason for this is that a PM > domain may be a subdomain of another and so we need to remove the child > PM domains for a given domain first. By removing PM domains in reverse > order we can ensure that the children are removed first. > > Add a new function to get the last PM domain that was added. In case PM > domains are added by more than one device in the system (for example, > on-chip domains and off-chip domains) add a 'owner' device structure > to the generic PM domain structure so that the ownership of a PM domain > can be identified by the device structure of the device that added it > Use this 'owner' device structure to return the last PM domain added by > this device. > > Note that because pm_genpd_init() simply adds each PM domain to the > head of the gpd_list object, list_for_each_entry() will start from the > last PM domain added. > > Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx> I don't have a strong opinion about what to call the device structure. Both "owner" or "dev" is okay by me. Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Kind regards Uffe > --- > This is the outcome from a discussion I had with Ulf on how best to > handle the removal of power-domains [0]. I opted to call the device > structure 'owner' because 'parent' could be misleading if a power > domain is a child of another power domain. However, open to suggestions! > > [0] http://marc.info/?l=linux-pm&m=145460070816340&w=2 > > drivers/base/power/domain.c | 25 +++++++++++++++++++++++++ > include/linux/pm_domain.h | 7 +++++++ > 2 files changed, 32 insertions(+) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index ea9f2aa3fc33..608bc00655ee 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -65,6 +65,31 @@ struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev) > } > > /* > + * Get the last generic PM domain added whose 'owner' device structure > + * matches the device structure provided. The 'owner' device structure > + * for a given PM domain should be initialised by the device that is > + * creating the PM domains and hence, calling pm_genpd_init(). > + */ > +struct generic_pm_domain *pm_genpd_list_get_tail(struct device *dev) > +{ > + struct generic_pm_domain *genpd = NULL, *gpd; > + > + if (IS_ERR_OR_NULL(dev)) > + return NULL; > + > + mutex_lock(&gpd_list_lock); > + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { > + if (gpd->owner == dev) { > + genpd = gpd; > + break; > + } > + } > + mutex_unlock(&gpd_list_lock); > + > + return genpd; > +} > + > +/* > * This should only be used where we are certain that the pm_domain > * attached to the device is a genpd domain. > */ > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index 49cd8890b873..b38dd74dea9b 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -46,6 +46,7 @@ struct genpd_power_state { > > struct generic_pm_domain { > struct dev_pm_domain domain; /* PM domain operations */ > + struct device *owner; /* Identity of the domain owner */ > struct list_head gpd_list_node; /* Node in the global PM domains list */ > struct list_head master_links; /* Links with PM domain as a master */ > struct list_head slave_links; /* Links with PM domain as a slave */ > @@ -120,6 +121,7 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev) > } > > extern struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev); > +extern struct generic_pm_domain *pm_genpd_list_get_tail(struct device *dev); > extern int __pm_genpd_add_device(struct generic_pm_domain *genpd, > struct device *dev, > struct gpd_timing_data *td); > @@ -145,6 +147,11 @@ static inline struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev) > { > return NULL; > } > +static inline > +struct generic_pm_domain *pm_genpd_list_get_tail(struct device *dev) > +{ > + return NULL; > +} > static inline int __pm_genpd_add_device(struct generic_pm_domain *genpd, > struct device *dev, > struct gpd_timing_data *td) > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
