Two power buttons detected

anatolik · 2019-12-13 05:54:07

I am trying to setup a logind.conf action on power key. I set `HandlePowerKey=suspend` but it did not make any change.

`evtest` shows that there are two power buttons at my system:

/dev/input/event1:	Power Button
/dev/input/event2:	Power Button

and the real button sends events to /dev/input/event2. I wonder if systemd listens for the first event source.

Here is part of my bootlog that shows the system detected two power buttons:

Dec 12 10:22:52 archlinux kernel: input: Sleep Button as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0E:00/input/input0
Dec 12 10:22:52 archlinux kernel: ACPI: Sleep Button [SLPB]
Dec 12 10:22:52 archlinux kernel: input: Power Button as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0C:00/input/input1
Dec 12 10:22:52 archlinux kernel: ACPI: Power Button [PWRB]
Dec 12 10:22:52 archlinux kernel: input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input2
Dec 12 10:22:52 archlinux kernel: ACPI: Power Button [PWRF]

And here is corresponding part of /proc/bus/input/devices:

I: Bus=0019 Vendor=0000 Product=0001 Version=0000
N: Name="Power Button"
P: Phys=PNP0C0C/button/input0
S: Sysfs=/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0C:00/input/input1
U: Uniq=
H: Handlers=kbd event1 
B: PROP=0
B: EV=3
B: KEY=10000000000000 0

I: Bus=0019 Vendor=0000 Product=0001 Version=0000
N: Name="Power Button"
P: Phys=LNXPWRBN/button/input0
S: Sysfs=/devices/LNXSYSTM:00/LNXPWRBN:00/input/input2
U: Uniq=
H: Handlers=kbd event2 
B: PROP=0
B: EV=3
B: KEY=10000000000000 0

Why does linux detects 2 buttons if my system has only 1 powerbutton? My motherboard is ASUS PRIME Z270-A. The BIOS is uptodate.

Last edited by anatolik (2019-12-13 05:55:31)

ChaManO · 2019-12-22 12:54:57

Hi,
This is a guess, but after seeing pictures from your motherboard model, I've seen that there is a two position switch located just above the front panel headers. That could be your first button. Try cycling it with evtest running to see if it's mapped to input1.
You'd probably have to write an udev rule to have it recognized as a different switch.

anatolik · 2019-12-23 18:55:49

ChaManO, the jumper above the panels header is CLRTC or "Clear RTC RAM jumper". It is definitely not the power button connector.

But there is an on-board PWR_SW button that sounds like it is "the first power button". Will check it with evtest.
UPDATE: PWR_SW does not produce any evtest events.

Last edited by anatolik (2019-12-24 05:24:43)

Arch Linux

#1 2019-12-13 05:54:07

Two power buttons detected

#2 2019-12-22 12:54:57

Re: Two power buttons detected

#3 2019-12-23 18:55:49

Re: Two power buttons detected

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