Hi Nishanth, Thanks for the review comments.
On Mon, May 19, 2014 at 6:43 PM, Nishanth Menon <n...@ti.com> wrote: > On 05/16/2014 04:09 AM, Inderpal Singh wrote: >> At the driver unloading time the associated opp table may need >> to be deleted. Otherwise it amounts to memory leak. The existing >> OPP library does not have provison to do so. >> >> Hence this patch implements the function to free the opp table. >> >> Signed-off-by: Inderpal Singh <inderpa...@samsung.com> >> --- >> drivers/base/power/opp.c | 41 +++++++++++++++++++++++++++++++++++++++++ >> include/linux/pm_opp.h | 6 ++++++ >> 2 files changed, 47 insertions(+) >> >> diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c >> index d9e376a..d45ffd5 100644 >> --- a/drivers/base/power/opp.c >> +++ b/drivers/base/power/opp.c >> @@ -654,4 +654,45 @@ int of_init_opp_table(struct device *dev) >> return 0; >> } >> EXPORT_SYMBOL_GPL(of_init_opp_table); >> + >> +/** >> + * dev_pm_opp_free_opp_table() - free the opp table >> + * @dev: device for which we do this operation >> + * >> + * Free up the allocated opp table >> + * >> + * Locking: The internal device_opp and opp structures are RCU protected. >> + * Hence this function internally uses RCU updater strategy with mutex >> locks to >> + * keep the integrity of the internal data structures. Callers should ensure >> + * that this function is *NOT* called under RCU protection or in contexts >> where >> + * mutex locking or synchronize_rcu() blocking calls cannot be used. >> + */ >> +void dev_pm_opp_free_opp_table(struct device *dev) >> +{ >> + struct device_opp *dev_opp = NULL; >> + struct dev_pm_opp *opp; >> + > if (!dev) > return; > missed it. Will take care in the next version. >> + /* Hold our list modification lock here */ >> + mutex_lock(&dev_opp_list_lock); >> + >> + /* Check for existing list for 'dev' */ >> + dev_opp = find_device_opp(dev); >> + if (IS_ERR(dev_opp)) { >> + mutex_unlock(&dev_opp_list_lock); >> + return; >> + } >> + >> + while (!list_empty(&dev_opp->opp_list)) { >> + opp = list_entry_rcu(dev_opp->opp_list.next, >> + struct dev_pm_opp, node); >> + list_del_rcu(&opp->node); >> + kfree_rcu(opp, head); >> + } > > How about the OPP notifiers? should'nt we add a new event > OPP_EVENT_REMOVE? > As this function is to free the whole opp table. Hence, I think, notifier may not be needed. It may be required for per opp removal as is the case with opp addition and enable/disable. But at present there are no users of these notifiers at all. Let me know your view. > To maintain non-dt behavior coherency, should'nt we rather add a > opp_remove or an opp_del function? Yes we should have opp_remove as well, but what's the use case ? Should we go ahead and implement it Or, wait for the use-case? Thanks, Inder > >> + >> + list_del_rcu(&dev_opp->node); >> + mutex_unlock(&dev_opp_list_lock); >> + synchronize_rcu(); >> + kfree(dev_opp); >> +} >> +EXPORT_SYMBOL_GPL(dev_pm_opp_free_opp_table); >> #endif >> diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h >> index 0330217..3c29620 100644 >> --- a/include/linux/pm_opp.h >> +++ b/include/linux/pm_opp.h >> @@ -50,6 +50,8 @@ int dev_pm_opp_enable(struct device *dev, unsigned long >> freq); >> int dev_pm_opp_disable(struct device *dev, unsigned long freq); >> >> struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev); >> + >> +void dev_pm_opp_free_opp_table(struct device *dev); >> #else >> static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) >> { >> @@ -105,6 +107,10 @@ static inline struct srcu_notifier_head >> *dev_pm_opp_get_notifier( >> { >> return ERR_PTR(-EINVAL); >> } >> + >> +void dev_pm_opp_free_opp_table(struct device *dev) >> +{ >> +} >> #endif /* CONFIG_PM_OPP */ >> >> #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF) >> > > > -- > Regards, > Nishanth Menon > -- > To unsubscribe from this list: send the line "unsubscribe linux-pm" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/