Raspberry Pi 500+: power button detected but no KEY_POWER events generated (kernel 6.12.x)

[4Misi]

Describe the bug

On Raspberry Pi 500+, running Raspberry Pi OS (Trixie / Debian 13) with kernel 6.12.x,
the built-in power button is detected by the kernel but does not generate any
KEY_POWER input events.

The input device appears correctly under /dev/input, but pressing the power button
produces no events at all. As a result, systemd-logind never receives a power key
event and no shutdown or power action occurs.

This appears to be a kernel-level regression affecting the pwr_button input device
on Raspberry Pi 500+.

Steps to reproduce the behaviour

1. Boot Raspberry Pi 500+ with Raspberry Pi OS (Trixie).
2. Verify the power button input device exists:
   ls -l /dev/input/by-path | grep pwr
3. Run:
   sudo evtest /dev/input/event5 (or the corresponding pwr_button event device)
4. Press the physical power button.

No events are generated.

Device (s)

Raspberry Pi 500+

System

OS: Raspberry Pi OS (Trixie / Debian 13)
Architecture: aarch64

Kernel:
Linux raspberrypi 6.12.47+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1~bookworm aarch64

Firmware:
(vcgenmd version output can be provided if required)

Logs

evtest output:

Input device name: "pwr_button"
Supported events:
Event type 1 (EV_KEY)
Event code 116 (KEY_POWER)

Pressing the power button produces no output.

Additional context

• The input device is present and registered:
  input:input5 "pwr_button"
• systemd-logind is using default configuration (HandlePowerKey=poweroff).
• User-space configuration and triggerhappy were ruled out.
• The issue persists after restoring a clean system configuration.

This strongly suggests a kernel or driver regression rather than a user-space issue.

[pelwell]

I'm running a fresh Trixie desktop installation on a Pi 500+ and the same kernel as you, and it's working for me.

Try this:

• In one window fire up your usual evtest (for me it was event0, but I think what you were doing is correct for you).
• In another window run pinctrl poll PWR_GPIO.
• Push and hold (just for a second or two) the PWR key. You should see pinctrl report that the input goes low when you press the key, then high when you release it. At the same time you should get a KEY_POWER 1 (pressed), then KEY_POWER 0 (released).