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authorKrzysztof Kozlowski <k.kozlowski@samsung.com>2015-06-08 04:09:48 +0300
committerSebastian Reichel <sre@kernel.org>2015-06-10 17:10:59 +0300
commit5c6e3a97e969e978368df83239583771c936efea (patch)
tree53578900b4a342b85b32e889504b7160c5ab7c1e /include/linux/power_supply.h
parentfb323eccbcaff06c1ed21ab989198eb40df6e846 (diff)
downloadlinux-5c6e3a97e969e978368df83239583771c936efea.tar.xz
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>
Diffstat (limited to 'include/linux/power_supply.h')
-rw-r--r--include/linux/power_supply.h5
1 files changed, 5 insertions, 0 deletions
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);