control file gets overwritten

[hellfi]

Hi!
I have an older Redmi 3s with a fresh Lineageos 16 where $something is overwriting the control file. Some crude debug in the shell, while being connected to power:
cat /sys/class/power_supply/battery/charging_enabled \ && echo 0 > /sys/class/power_supply/battery/charging_enabled \ && cat /sys/class/power_supply/battery/charging_enabled \ && sleep 1s \ && cat /sys/class/power_supply/battery/charging_enabled
produces

1
0
1

So even when the file is altered by BatteryChargeLimit once it reaches the limit this only lasts a second. My crude remedy: make the control file not writable:
cat /sys/class/power_supply/battery/charging_enabled \ && echo 0 > /sys/class/power_supply/battery/charging_enabled \ && chmod -w /sys/class/power_supply/battery/charging_enabled \ && cat /sys/class/power_supply/battery/charging_enabled \ && sleep 3s \ && cat /sys/class/power_supply/battery/charging_enabled

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Reversing this enables charging again.
I'm not confident playing with access rights on the control file is the way to go, but after the battery dies it should get reset in the worst case, being in /sys/. Maybe something like this could be added with even more warning dialogs to confirm?