power_supply: sysfs: Bring back write to writeable properties

Browse source

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: 8e59c7f234 ("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>

...

This commit is contained in:

Krzysztof Kozlowski 2015-06-08 10:09:48 +09:00 • committed by Sebastian Reichel

parent fb323eccbc

commit 5c6e3a97e9

2 changed files with 6 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

5

include/linux/power_supply.h

View file