Arch Linux

Kotrfa

Member

Registered: 2012-10-25

Posts: 213

Workaround for bug (ACPI, Power supply)

Hi.

I'm using Arch on Samsung 530U and there is bug in handling with power supply. It is reported for example here: https://bugs.launchpad.net/bugs/971061, https://bugs.launchpad.net/bugs/1027798 etc.

Samsung's replies on my urgents to fix it are: "Use windows..."

In short - problem is that system remember if the battery is charging/discharging only at boot (I guess when acpi starts) and since than it is frozen. But the recognition of pluging/unpluging power supply works fine.

Here is what is does, when cable was plugged at start:

Battery is fully charged and adapter is connected:

~$ acpi -V
Battery 0: Unknown, 80%
Battery 0: design capacity 6100 mAh, last full capacity 6100 mAh = 100%
Adapter 0: on-line
----------
~$  cat /sys/class/power_supply/BAT1/status
Unknown
----------
~$  cat /sys/class/power_supply/ADP1/online 
1

When the adapter is disconnected:

Battery 0: Charging, 80%, charging at zero rate - will never fully charge.
Battery 0: design capacity 6100 mAh, last full capacity 6100 mAh = 100%
Adapter 0: off-line
-----------------
~$ cat /sys/class/power_supply/BAT1/status
Charging
-----------------
~$ cat /sys/class/power_supply/ADP1/online
0

You can see that adapter is recognized well, but the battery still "thinks" it has been charging. I can't see how much time is remaining etc.

When I manually try 'sudo echo "Discharging" >> /sys/class/power_supply/BAT1/status' I get permission denied.

Any ideas or workaround?

Thanks

Last edited by Kotrfa (2013-04-16 08:38:10)