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author | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2015-03-12 10:44:12 +0300 |
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committer | Sebastian Reichel <sre@kernel.org> | 2015-03-14 01:15:52 +0300 |
commit | 1a352462b5377ac68f5955d674b3460c7bac52a3 (patch) | |
tree | b2dbecd8b038ccaddd262af47efa4fdf64c75696 /drivers/power/power_supply_core.c | |
parent | 297d716f6260cc9421d971b124ca196b957ee458 (diff) | |
download | linux-1a352462b5377ac68f5955d674b3460c7bac52a3.tar.xz |
power_supply: Add power_supply_put for decrementing device reference counter
The power_supply_get_by_phandle() and power_supply_get_by_name() use
function class_find_device() for obtaining the reference to power
supply. Each use of class_find_device() increases the power supply's
device reference counter.
However the reference counter was not decreased by users of this API.
Thus final device_unregister() call from power_supply_unregister() could
not release the device and clean up its resources. This lead to memory
leak if at least once power_supply_get_by_*() was called between
registering and unregistering the power supply.
Add and document new API power_supply_put() for decrementing the
reference counter.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Diffstat (limited to 'drivers/power/power_supply_core.c')
-rw-r--r-- | drivers/power/power_supply_core.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index e51405b176c8..b4ec14683b7f 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -336,6 +336,17 @@ static int power_supply_match_device_by_name(struct device *dev, const void *dat return strcmp(psy->desc->name, name) == 0; } +/** + * power_supply_get_by_name() - Search for a power supply and returns its ref + * @name: Power supply name to fetch + * + * If power supply was found, it increases reference count for the + * internal power supply's device. The user should power_supply_put() + * after usage. + * + * Return: On success returns a reference to a power supply with + * matching name equals to @name, a NULL otherwise. + */ struct power_supply *power_supply_get_by_name(const char *name) { struct device *dev = class_find_device(power_supply_class, NULL, name, @@ -345,12 +356,39 @@ struct power_supply *power_supply_get_by_name(const char *name) } EXPORT_SYMBOL_GPL(power_supply_get_by_name); +/** + * power_supply_put() - Drop reference obtained with power_supply_get_by_name + * @psy: Reference to put + * + * The reference to power supply should be put before unregistering + * the power supply. + */ +void power_supply_put(struct power_supply *psy) +{ + might_sleep(); + + put_device(&psy->dev); +} +EXPORT_SYMBOL_GPL(power_supply_put); + #ifdef CONFIG_OF static int power_supply_match_device_node(struct device *dev, const void *data) { return dev->parent && dev->parent->of_node == data; } +/** + * power_supply_get_by_phandle() - Search for a power supply and returns its ref + * @np: Pointer to device node holding phandle property + * @phandle_name: Name of property holding a power supply name + * + * If power supply was found, it increases reference count for the + * internal power supply's device. The user should power_supply_put() + * after usage. + * + * Return: On success returns a reference to a power supply with + * matching name equals to value under @property, NULL or ERR_PTR otherwise. + */ struct power_supply *power_supply_get_by_phandle(struct device_node *np, const char *property) { |