From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Date: Mon, 8 Jun 2015 01:09:48 +0000 (+0900)
Subject: power_supply: sysfs: Bring back write to writeable properties
X-Git-Tag: omap-for-v4.2/fixes-rc1^2~149^2~8
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c6e3a97e969e978368df83239583771c936efea;p=pandora-kernel.git

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>
---

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