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 be6299c6e55e ("power: supply: sysfs: use power_supply_property_is_writeable()") this now also impacts power_supply class sysfs attributes.
Fixes: be6299c6e55e ("power: supply: sysfs: use power_supply_property_is_writeable()") Fixes: e67d4dfc9ff1 ("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 --- The fixing of be6299c6e55e is a 6.11 regression fix, the fixing of e67d4dfc9ff1 hwmon attr never being writable is a stable series fix.
This supersedes the "power: supply: sysfs: Revert use power_supply_property_is_writeable()" patch. --- drivers/power/supply/power_supply_core.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 0417fb34e846..49534458a9f7 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -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);