power: supply: Drop use_cnt check from power_supply_property_is_writeable()

power_supply_property_is_writeable() gets called from the is_visible()
callback for the sysfs attributes of power_supply class devices and for
the sysfs attributes of power_supply core instantiated hwmon class devices.

These sysfs attributes get registered by the device_add() respectively
power_supply_add_hwmon_sysfs() calls in power_supply_register().

use_cnt gets initialized to 0 and is incremented only after these calls.
So when power_supply_property_is_writeable() gets called it always return
-ENODEV because of use_cnt == 0.

This causes all the attributes to have permissions of 444 even those which
should be writable. This used to be a problem only for hwmon sysfs
attributes but since commit be6299c6e5 ("power: supply: sysfs: use
power_supply_property_is_writeable()") this now also impacts power_supply
class sysfs attributes.

Fixes: be6299c6e5 ("power: supply: sysfs: use power_supply_property_is_writeable()")
Fixes: e67d4dfc9f ("power: supply: Add HWMON compatibility layer")
Cc: stable@vger.kernel.org
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/stable/20240908185337.103696-1-hdegoede%40redhat.com
Link: https://lore.kernel.org/r/20240908185337.103696-1-hdegoede@redhat.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
This commit is contained in:
Hans de Goede 2024-09-08 20:53:36 +02:00 committed by Sebastian Reichel
parent eb1ea1351d
commit 78f281e5bd

View File

@ -1231,11 +1231,7 @@ EXPORT_SYMBOL_GPL(power_supply_set_property);
int power_supply_property_is_writeable(struct power_supply *psy,
enum power_supply_property psp)
{
if (atomic_read(&psy->use_cnt) <= 0 ||
!psy->desc->property_is_writeable)
return -ENODEV;
return psy->desc->property_is_writeable(psy, psp);
return psy->desc->property_is_writeable && psy->desc->property_is_writeable(psy, psp);
}
EXPORT_SYMBOL_GPL(power_supply_property_is_writeable);