diff options
Diffstat (limited to 'drivers/power/power_supply_core.c')
| -rw-r--r-- | drivers/power/power_supply_core.c | 100 |
1 files changed, 47 insertions, 53 deletions
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index 078afd61490d..6cb7fe5c022d 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -58,7 +58,7 @@ static bool __power_supply_is_supplied_by(struct power_supply *supplier, static int __power_supply_changed_work(struct device *dev, void *data) { - struct power_supply *psy = (struct power_supply *)data; + struct power_supply *psy = data; struct power_supply *pst = dev_get_drvdata(dev); if (__power_supply_is_supplied_by(psy, pst)) { @@ -78,7 +78,14 @@ static void power_supply_changed_work(struct work_struct *work) dev_dbg(psy->dev, "%s\n", __func__); spin_lock_irqsave(&psy->changed_lock, flags); - if (psy->changed) { + /* + * Check 'changed' here to avoid issues due to race between + * power_supply_changed() and this routine. In worst case + * power_supply_changed() can be called again just before we take above + * lock. During the first call of this routine we will mark 'changed' as + * false and it will stay false for the next call as well. + */ + if (likely(psy->changed)) { psy->changed = false; spin_unlock_irqrestore(&psy->changed_lock, flags); class_for_each_device(power_supply_class, NULL, psy, @@ -89,12 +96,13 @@ static void power_supply_changed_work(struct work_struct *work) kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE); spin_lock_irqsave(&psy->changed_lock, flags); } + /* - * Dependent power supplies (e.g. battery) may have changed state - * as a result of this event, so poll again and hold the - * wakeup_source until all events are processed. + * Hold the wakeup_source until all events are processed. + * power_supply_changed() might have called again and have set 'changed' + * to true. */ - if (!psy->changed) + if (likely(!psy->changed)) pm_relax(psy->dev); spin_unlock_irqrestore(&psy->changed_lock, flags); } @@ -119,7 +127,7 @@ EXPORT_SYMBOL_GPL(power_supply_changed); static int __power_supply_populate_supplied_from(struct device *dev, void *data) { - struct power_supply *psy = (struct power_supply *)data; + struct power_supply *psy = data; struct power_supply *epsy = dev_get_drvdata(dev); struct device_node *np; int i = 0; @@ -127,7 +135,7 @@ static int __power_supply_populate_supplied_from(struct device *dev, do { np = of_parse_phandle(psy->of_node, "power-supplies", i++); if (!np) - continue; + break; if (np == epsy->of_node) { dev_info(psy->dev, "%s: Found supply : %s\n", @@ -158,12 +166,12 @@ static int power_supply_populate_supplied_from(struct power_supply *psy) static int __power_supply_find_supply_from_node(struct device *dev, void *data) { - struct device_node *np = (struct device_node *)data; + struct device_node *np = data; struct power_supply *epsy = dev_get_drvdata(dev); - /* return error breaks out of class_for_each_device loop */ + /* returning non-zero breaks out of class_for_each_device loop */ if (epsy->of_node == np) - return -EINVAL; + return 1; return 0; } @@ -171,30 +179,21 @@ static int __power_supply_find_supply_from_node(struct device *dev, static int power_supply_find_supply_from_node(struct device_node *supply_node) { int error; - struct device *dev; - struct class_dev_iter iter; /* - * Use iterator to see if any other device is registered. - * This is required since class_for_each_device returns 0 - * if there are no devices registered. - */ - class_dev_iter_init(&iter, power_supply_class, NULL, NULL); - dev = class_dev_iter_next(&iter); - - if (!dev) - return -EPROBE_DEFER; - - /* - * We have to treat the return value as inverted, because if - * we return error on not found, then it won't continue looking. - * So we trick it by returning error on success to stop looking - * once the matching device is found. + * class_for_each_device() either returns its own errors or values + * returned by __power_supply_find_supply_from_node(). + * + * __power_supply_find_supply_from_node() will return 0 (no match) + * or 1 (match). + * + * We return 0 if class_for_each_device() returned 1, -EPROBE_DEFER if + * it returned 0, or error as returned by it. */ error = class_for_each_device(power_supply_class, NULL, supply_node, __power_supply_find_supply_from_node); - return error ? 0 : -EPROBE_DEFER; + return error ? (error == 1 ? 0 : error) : -EPROBE_DEFER; } static int power_supply_check_supplies(struct power_supply *psy) @@ -215,17 +214,21 @@ static int power_supply_check_supplies(struct power_supply *psy) np = of_parse_phandle(psy->of_node, "power-supplies", cnt++); if (!np) - continue; + break; ret = power_supply_find_supply_from_node(np); + of_node_put(np); + if (ret) { - dev_dbg(psy->dev, "Failed to find supply, defer!\n"); - of_node_put(np); - return -EPROBE_DEFER; + dev_dbg(psy->dev, "Failed to find supply!\n"); + return ret; } - of_node_put(np); } while (np); + /* Missing valid "power-supplies" entries */ + if (cnt == 1) + return 0; + /* All supplies found, allocate char ** array for filling */ psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from), GFP_KERNEL); @@ -234,7 +237,7 @@ static int power_supply_check_supplies(struct power_supply *psy) return -ENOMEM; } - *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * cnt, + *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * (cnt - 1), GFP_KERNEL); if (!*psy->supplied_from) { dev_err(psy->dev, "Couldn't allocate memory for supply list\n"); @@ -253,14 +256,12 @@ static inline int power_supply_check_supplies(struct power_supply *psy) static int __power_supply_am_i_supplied(struct device *dev, void *data) { union power_supply_propval ret = {0,}; - struct power_supply *psy = (struct power_supply *)data; + struct power_supply *psy = data; struct power_supply *epsy = dev_get_drvdata(dev); if (__power_supply_is_supplied_by(epsy, psy)) - if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) { - if (ret.intval) - return ret.intval; - } + if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) + return ret.intval; return 0; } @@ -285,12 +286,10 @@ static int __power_supply_is_system_supplied(struct device *dev, void *data) unsigned int *count = data; (*count)++; - if (psy->type != POWER_SUPPLY_TYPE_BATTERY) { - if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret)) - return 0; - if (ret.intval) + if (psy->type != POWER_SUPPLY_TYPE_BATTERY) + if (!psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret)) return ret.intval; - } + return 0; } @@ -423,9 +422,7 @@ static int psy_register_thermal(struct power_supply *psy) if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) { psy->tzd = thermal_zone_device_register(psy->name, 0, 0, psy, &psy_tzd_ops, NULL, 0, 0); - if (IS_ERR(psy->tzd)) - return PTR_ERR(psy->tzd); - break; + return PTR_ERR_OR_ZERO(psy->tzd); } } return 0; @@ -503,9 +500,7 @@ static int psy_register_cooler(struct power_supply *psy) psy->tcd = thermal_cooling_device_register( (char *)psy->name, psy, &psy_tcd_ops); - if (IS_ERR(psy->tcd)) - return PTR_ERR(psy->tcd); - break; + return PTR_ERR_OR_ZERO(psy->tcd); } } return 0; @@ -591,7 +586,7 @@ static int __power_supply_register(struct device *parent, power_supply_changed(psy); - goto success; + return 0; create_triggers_failed: psy_unregister_cooler(psy); @@ -604,7 +599,6 @@ wakeup_init_failed: check_supplies_failed: dev_set_name_failed: put_device(dev); -success: return rc; } |