Battery applet: support multiple batteries

[gijsbers]

battery applet can't find power_supply. How can I fix this?

[jmc-88]

The battery applet looks for per-battery paths in sysfs: https://github.com/jmc-88/tint3/blob/8cf54fe8c1a0d1b8d05808ac3fd64e072b7d2c29/src/battery/linux_sysfs.cc#L8

• Does your kernel support it? (CONFIG_SYSFS)
• Is it mounted? (if not, mount -t sysfs sysfs /sys)
• What does it contain? (ls -R /sys/class/power_supply)

We can start from here and see what's wrong. And possibly I should add more useful error messages. :)

[gijsbers]

I now have:

# ls -R /sys/class/power_supply   
/sys/class/power_supply:
AC0  BAT0  BAT1

tint3 only shows me the first, but not the second?

[jmc-88]

Yes, multiple battery support is to do: https://github.com/jmc-88/tint3/blob/master/src/battery/battery.cc#L190

I didn't prioritize that as you're the first one to request support for it, and I don't have a device with two batteries to test this against. I'll keep this bug open to track that.

[jmc-88]

My understanding is that tint2 shows a single battery applet with the aggregated status, not separate battery applets. Can you confirm?

[gijsbers]

tint2 output:

Found mains "AC0"
tint2: Found power device BAT0
tint2: /y/src/panelapplets/tint2/src/battery/linux.c:155: read failed
tint2: Failed to initialize battery "BAT0"
tint2: Found power device BAT1
tint2: /y/src/panelapplets/tint2/src/battery/linux.c:155: read failed
tint2: Failed to initialize battery "BAT1"

[o9000]

If I may pitch in, I think it would be very useful for both projects (tint3 and tint2) to see the contents of /sys/class/power_supply on your machine. The following command will save it to a file called battery.txt:

bash -c "exec 1>battery.txt; exec 2>&1; for d in /sys/class/power_supply/* ; do find $d/ -exec sh -c 'echo {} ; cat {} ' ';' ; done"

Could you please post that here?

@jmc-88:

I have a script that converts this file back into a directory, and a couple of such directories here. Tint2 accepts the undocumented CLI argument --battery-sys-prefix that replaces /sys/class/power_supply with the given path, to test the code on that data.

[gijsbers]

That script never ended, producing endless output. I have an improvement for you: cd /sys/devices/virtual/power_supply/ && grep -r '' bat.zip

[o9000]

Thank you!

Regarding tint2, I fixed that problem with initializing the batteries. It was caused by not handling gracefully the lack of charging rate data (current) on your system.

I have also added to the repository your data files, in https://gitlab.com/o9000/tint2/tree/master/test/2battery-gijsbers Hopefully this will help with adding multi-battery support in tint3.