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| author |   Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2015-03-12 08:44:13 +0100 |
|---|---|---|
| committer |   Sebastian Reichel <sre@kernel.org> | 2015-03-13 23:15:52 +0100 |
| commit | 03e81acce5568c7105dc5bef6984c8b0edfe8d45 (patch) | |
| tree | 5a23f5c2245e9d4f170e644e2050638c225b51a1 | |
| parent | power_supply: Add power_supply_put for decrementing device reference counter (diff) | |
| download | linux-dev-03e81acce5568c7105dc5bef6984c8b0edfe8d45.tar.xz linux-dev-03e81acce5568c7105dc5bef6984c8b0edfe8d45.zip | |
power_supply: Increment power supply use counter when obtaining references
Increment the power_supply.use_cnt usage counter on:
- power_supply_get_by_phandle()
- power_supply_get_by_name()
and decrement it on power_supply_put() call.
This helps tracking of valid usage of power supply instance by
consumers. The usage counter itself also allows safe calling of
power_supply_get_property-like functions even when driver unregisters
this power supply.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
| -rw-r--r-- | drivers/power/power_supply_core.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index b4ec14683b7f..2ed4a4a6b3c5 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -349,10 +349,16 @@ static int power_supply_match_device_by_name(struct device *dev, const void *dat */ struct power_supply *power_supply_get_by_name(const char *name) { + struct power_supply *psy = NULL; struct device *dev = class_find_device(power_supply_class, NULL, name, power_supply_match_device_by_name); - return dev ? dev_get_drvdata(dev) : NULL; + if (dev) { + psy = dev_get_drvdata(dev); + atomic_inc(&psy->use_cnt); + } + + return psy; } EXPORT_SYMBOL_GPL(power_supply_get_by_name); @@ -367,6 +373,7 @@ void power_supply_put(struct power_supply *psy) { might_sleep(); + atomic_dec(&psy->use_cnt); put_device(&psy->dev); } EXPORT_SYMBOL_GPL(power_supply_put); @@ -393,6 +400,7 @@ struct power_supply *power_supply_get_by_phandle(struct device_node *np, const char *property) { struct device_node *power_supply_np; + struct power_supply *psy = NULL; struct device *dev; power_supply_np = of_parse_phandle(np, property, 0); @@ -404,7 +412,12 @@ struct power_supply *power_supply_get_by_phandle(struct device_node *np, of_node_put(power_supply_np); - return dev ? dev_get_drvdata(dev) : NULL; + if (dev) { + psy = dev_get_drvdata(dev); + atomic_inc(&psy->use_cnt); + } + + return psy; } EXPORT_SYMBOL_GPL(power_supply_get_by_phandle); #endif /* CONFIG_OF */ |