[PATCH 6.11 regression fix 1/2] power: supply: Drop use_cnt check from power_supply_property_is_writeable()

[PATCH 6.11 regression fix 1/2] power: supply: Drop use_cnt check from power_supply_property_is_writeable()

[Hans de Goede]

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);
 
-- 
2.46.0

[PATCH 2/2] power: supply: hwmon: Fix missing temp1_max_alarm attribute

[Hans de Goede]

Temp channel 0 aka temp1 can have a temp1_max_alarm attribute for
power_supply devices which have a POWER_SUPPLY_PROP_TEMP_ALERT_MAX
property.

HWMON_T_MAX_ALARM was missing from power_supply_hwmon_info for
temp channel 0, causing the hwmon temp1_max_alarm attribute to be
missing from such power_supply devices.

Add this to power_supply_hwmon_info to fix this.

Fixes: f1d33ae806ec ("power: supply: remove duplicated argument in power_supply_hwmon_info")
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
The original code accidentally listed HWMON_T_MIN_ALARM twice instead
of having HWMON_T_MIN_ALARM + HWMON_T_MAX_ALARM. Commit f1d33ae806ec
fixed this the wrong way by removing the second MIN_ALARM.
---
 drivers/power/supply/power_supply_hwmon.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/power_supply_hwmon.c b/drivers/power/supply/power_supply_hwmon.c
index baacefbdf768..6fbbfb1c685e 100644
--- a/drivers/power/supply/power_supply_hwmon.c
+++ b/drivers/power/supply/power_supply_hwmon.c
@@ -318,7 +318,8 @@ static const struct hwmon_channel_info * const power_supply_hwmon_info[] = {
 			   HWMON_T_INPUT     |
 			   HWMON_T_MAX       |
 			   HWMON_T_MIN       |
-			   HWMON_T_MIN_ALARM,
+			   HWMON_T_MIN_ALARM |
+			   HWMON_T_MAX_ALARM,
 
 			   HWMON_T_LABEL     |
 			   HWMON_T_INPUT     |
-- 
2.46.0

Re: [PATCH 6.11 regression fix 1/2] power: supply: Drop use_cnt check from power_supply_property_is_writeable()

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-3

Rule: The upstream commit ID must be specified with a separate line above the commit text.
Subject: [PATCH 6.11 regression fix 1/2] power: supply: Drop use_cnt check from power_supply_property_is_writeable()
Link: https://lore.kernel.org/stable/20240908185337.103696-1-hdegoede%40redhat.com

Please ignore this mail if the patch is not relevant for upstream.

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 6.11 regression fix 1/2] power: supply: Drop use_cnt check from power_supply_property_is_writeable()

[Sebastian Reichel]

On Sun, 08 Sep 2024 20:53:36 +0200, Hans de Goede wrote:
> 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().
> 
> [...]

Applied, thanks!

[1/2] power: supply: Drop use_cnt check from power_supply_property_is_writeable()
      commit: 78f281e5bdeb6476fab97a2c3fcece1094b42aaf
[2/2] power: supply: hwmon: Fix missing temp1_max_alarm attribute
      commit: e50a57d16f897e45de1112eb6478577b197fab52

Best regards,
-- 
Sebastian Reichel <sebastian.reichel@collabora.com>