diff options
| -rw-r--r-- | drivers/base/power/opp.c | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 7895fdd64192..28d70c9f86ed 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -408,11 +408,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); /** - * _add_device_opp() - Allocate a new device OPP table + * _add_device_opp() - Find device OPP table or allocate a new one * @dev: device for which we do this operation * - * New device node which uses OPPs - used when multiple devices with OPP tables - * are maintained. + * It tries to find an existing table first, if it couldn't find one, it + * allocates a new OPP table and returns that. * * Return: valid device_opp pointer if success, else NULL. */ @@ -420,6 +420,11 @@ static struct device_opp *_add_device_opp(struct device *dev) { struct device_opp *dev_opp; + /* Check for existing list for 'dev' first */ + dev_opp = _find_device_opp(dev); + if (!IS_ERR(dev_opp)) + return dev_opp; + /* * Allocate a new device OPP table. In the infrequent case where a new * device is needed to be added, we pay this penalty. @@ -575,7 +580,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove); static int _opp_add_dynamic(struct device *dev, unsigned long freq, long u_volt, bool dynamic) { - struct device_opp *dev_opp = NULL; + struct device_opp *dev_opp; struct dev_pm_opp *opp, *new_opp; struct list_head *head; int ret; @@ -592,19 +597,11 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, new_opp->rate = freq; new_opp->u_volt = u_volt; new_opp->available = true; - new_opp->dynamic = dynamic; - - /* Check for existing list for 'dev' */ - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - dev_opp = _add_device_opp(dev); - if (!dev_opp) { - ret = -ENOMEM; - goto free_opp; - } - head = &dev_opp->opp_list; - goto list_add; + dev_opp = _add_device_opp(dev); + if (!dev_opp) { + ret = -ENOMEM; + goto free_opp; } /* @@ -612,15 +609,22 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, * and discard if already present */ head = &dev_opp->opp_list; + + /* + * Need to use &dev_opp->opp_list in the condition part of the 'for' + * loop, don't replace it with head otherwise it will become an infinite + * loop. + */ list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { - if (new_opp->rate <= opp->rate) - break; - else + if (new_opp->rate > opp->rate) { head = &opp->node; - } + continue; + } + + if (new_opp->rate < opp->rate) + break; - /* Duplicate OPPs ? */ - if (new_opp->rate == opp->rate) { + /* Duplicate OPPs */ ret = opp->available && new_opp->u_volt == opp->u_volt ? 0 : -EEXIST; @@ -630,7 +634,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, goto free_opp; } -list_add: + new_opp->dynamic = dynamic; new_opp->dev_opp = dev_opp; list_add_rcu(&new_opp->node, head); mutex_unlock(&dev_opp_list_lock); |