vpower logs errors to journal when current_now for BAT1 is 0 after suspending device while fully charged

[matte-schwartz]

Your system information

• Steam client version: 1726256783
• SteamOS version: 3.6.13
• Opted into Steam client beta?: Yes
• Opted into SteamOS beta?: Yes
• Have you checked for updates in Settings > System?: No

Please describe your issue in as much detail as possible:

When vpower queries BAT1 for current_now, if the device is plugged in and completed charging after rebooting, vpower will log a stream of read /sys/class/power_supply/BAT1/current_now: No such device (os error 19) to journal. If I manually check /sys/class/power_supply/BAT1/current_now I can see it report the value as 0. Is this error logging expected? I don't recall seeing it while on SteamOS 3.5 but I could be mistaken.

Steps for reproducing this issue:

1. Fully charge up Steam Deck (in my case, I'm using an OLED Deck)
2. Reboot the device after fully charged
3. You should start to see these vpower journal logs by now

Logs:

(130)(deck@steamdeck ~)$ sudo systemctl status vpower
● vpower.service - vpower daemon
     Loaded: loaded (/usr/lib/systemd/system/vpower.service; disabled; preset: disabled)
     Active: active (running) since Sun 2024-09-15 22:50:00 PDT; 11h ago
   Main PID: 676 (vpower)
      Tasks: 1 (limit: 17750)
     Memory: 996.0K (peak: 1.7M)
        CPU: 4.116s
     CGroup: /system.slice/vpower.service
             └─676 /usr/lib/vpower

Sep 16 09:35:58 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:35:59 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:00 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:01 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:02 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:03 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:04 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:05 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:06 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
Sep 16 09:36:07 steamdeck vpower[676]: read /sys/class/power_supply/BAT1/current_now: No such device (os error 19)
(deck@steamdeck ~)$ cat /sys/class/power_supply/BAT1/current_now 
0

System report: systemreport-20240916172120.txt