htop battery meter displays n/a

[bootzin]

I tried to find somehwere where I could edit the path htop searches for battery info but I couldn't find it, is this possible? My battery device is called CMB0 and it looks like htop only searches for BAT#

[Explorer09]

Please show us your ls output of /sys/class/power_supply

[bootzin]

ADP1 CMB0

[Explorer09]

Ok, this is weird. (The names in /sys/class/power_supply are not clearly documented in Linux. The CMB seems to refer to "Control Method battery" but the string is not included in any part of kernel source code.)

By the way, if you want to provide a patch, I can point you to the code that caused this:
It's Battery_getSysData() in htop source linux/Battery.c

[br3eze]

Hello. I had this issue once too.

"htop 2.0.1"
ls -l /sys/class/power_supply:
lrwxrwxrwx 1 root root 0 Jun 21 15:38 AC0 -> ../../devices/LNXSYSTM:00/device:00/PNP0A08:00/ACPI0003:00/power_supply/AC0/
lrwxrwxrwx 1 root root 0 Jun 22 16:04 BAT0 -> ../../devices/LNXSYSTM:00/device:00/PNP0A08:00/PNP0C0A:00/power_supply/BAT0/

[hishamhm]

Could you post the output of
grep '' /sys/class/power_supply/*/type ?

Thanks!

[br3eze]

/sys/class/power_supply/AC0/type:Mains
/sys/class/power_supply/BAT0/type:Battery

[yrro]

I think htop shouldn't concern itself with the name of the battery device. I think the name is just taken from the ACPI battery device and so it's up to manufacturer to decide on the name. htop should therefore consider any device with subsystem power_supply and type Battery. The future-proof way to obtain this is to ask libudev... if you walk through /sys yourself then you have to handle future changes in the layout (e.g., the change from /sys/class to /sys/subsystem)...

[Explorer09]

@yrro
I have asked where the /sys/subsystem folder is three years ago and I haven't seen that folder actually implemented. I would hate depending on libudev, since the kernel should have given us a stable sysfs interface to use. Checking for types rather than guessing on ACPI name pattern (the folder names just below /sys/class/power_supply are four-characters names from ACPI tables) is a good idea, but relying on a third-party library for that would be an overkill.