diff options
| author | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2015-06-08 10:09:48 +0900 |
|---|---|---|
| committer | Sebastian Reichel <sre@kernel.org> | 2015-06-10 16:10:59 +0200 |
| commit | 5c6e3a97e969e978368df83239583771c936efea (patch) | |
| tree | 53578900b4a342b85b32e889504b7160c5ab7c1e | |
| parent | fb323eccbcaff06c1ed21ab989198eb40df6e846 (diff) | |
power_supply: sysfs: Bring back write to writeable properties
The fix for NULL pointer exception related to calling uevent for not
finished probe caused to set all writeable properties as non-writeable.
This was caused by checking if property is writeable before the initial
increase of power supply usage counter and in the same time using
wrapper over property_is_writeable(). The wrapper returns ENODEV if the
usage counter is still 0.
The call trace looked like:
device probe:
power_supply_register()
use_cnt = 0;
device_add()
create sysfs entries
power_supply_attr_is_visible()
power_supply_property_is_writeable()
if (use_cnt == 0) return -ENODEV;
use_cnt++;
Replace the usage of wrapper with direct call to property_is_writeable()
from driver. This should be safe call during device probe because
implementations of this callback just return 0/1 for different
properties and they do not access any of the driver's internal data.
Fixes: 8e59c7f23410 ("power_supply: Fix NULL pointer dereference during bq27x00_battery probe")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
| -rw-r--r-- | drivers/power/power_supply_sysfs.c | 2 | ||||
| -rw-r--r-- | include/linux/power_supply.h | 5 |
2 files changed, 6 insertions, 1 deletions
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c index af026806cba5..ed2d7fd0c734 100644 --- a/drivers/power/power_supply_sysfs.c +++ b/drivers/power/power_supply_sysfs.c @@ -223,7 +223,7 @@ static umode_t power_supply_attr_is_visible(struct kobject *kobj, if (property == attrno) { if (psy->desc->property_is_writeable && - power_supply_property_is_writeable(psy, property) > 0) + psy->desc->property_is_writeable(psy, property) > 0) mode |= S_IWUSR; return mode; diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index a80f1fd01ddb..0395bcb18ddb 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -206,6 +206,11 @@ struct power_supply_desc { int (*set_property)(struct power_supply *psy, enum power_supply_property psp, const union power_supply_propval *val); + /* + * property_is_writeable() will be called during registration + * of power supply. If this happens during device probe then it must + * not access internal data of device (because probe did not end). + */ int (*property_is_writeable)(struct power_supply *psy, enum power_supply_property psp); void (*external_power_changed)(struct power_supply *psy); |