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The laptop that suspended two thousand times a day

· linux kernel acpi suspend lenovo

This laptop, a Lenovo Legion Pro 5 16ARX8, spends most of its life closed on a desk with an external display. Left alone it is supposed to lock, blank the display, and suspend. What it actually did, for days, was suspend and wake up again roughly every 30 seconds, all night, thousands of times.

Nobody noticed, because from the outside a laptop that resumes in two seconds looks exactly like a laptop that is asleep. What got noticed was something else entirely.

The setup🔗

The wrong symptom🔗

The thing that got noticed was a systemd user unit, omarchy-sleep-lock.service, whose job is to hold a sleep inhibitor and lock the screen before suspend. Its restart counter read 17,445. Its log was a wall of “Failed to inhibit: already running”, and it has Restart=always, so it was failing, restarting two seconds later, failing again.

The obvious conclusion is that the unit is broken. It is not. It fails about four times per suspend cycle, because during the short window when logind’s PrepareForSleep signal is in flight the inhibitor is legitimately taken, and the unit has no way to know that. Harmless on a machine that suspends twice a day. On a machine that suspends 2,221 times a day, which is what the journal showed for a single day, the counter looks like the disease. It was the fever.

The actual loop🔗

Reading logind’s log with the timestamps lined up made the shape clear:

  1. Lid closed, internal panel off, external display attached. The machine idles, locks, and five seconds after locking the lock screen blanks the external display.
  2. When the external display blanks, it drops off DRM entirely. logind now sees a closed lid and no external display, so Docked flips to false and HandleLidSwitch=suspend fires.
  3. The machine suspends. One to two seconds later it wakes up. The gap between logind’s “Suspending” and “finished” lines is 10 to 17 seconds, and all of it is pre-sleep work. The time actually asleep rounds to nothing.
  4. logind has a HoldoffTimeoutSec of 30 seconds after resume before it will act on the lid switch again. It expires. The lid is still closed. Go to 2.

That is about 109 cycles per hour. Across two days the journal showed 4,465 of them.

Finding the wake source🔗

Every suspend was being woken immediately by something. The kernel will say what, if asked:

echo 1 > /sys/power/pm_debug_messages

Then suspend once and read the kernel log:

PM: Triggering wakeup from IRQ 7
amd_gpio AMDI0030:00: GPIO 4 is active: 0x30057c00

IRQ 7 is the AMD GPIO controller’s interrupt. GPIO 4 is one of its pins, and the status register value has both the interrupt-status and wake-status bits set. The pin is described in ACPI as an event pin on AMDI0030:00, edge triggered and armed as an S3 wake source. Its interrupt count in /proc/interrupts was 4,494 against 4,466 suspends. Same number, give or take the handful of times it fired while awake.

Before getting there, two red herrings ate time. The AC adapter device and the embedded controller both looked plausible, both were wrong. The lid switch itself is handled by the embedded controller through ACPI query methods, not by this GPIO, which mattered later: ignoring the GPIO would not break lid wake.

What GPIO 4 actually is, the firmware does not say in a way the kernel can show. Its ACPI event handler lives in an SSDT rather than the DSDT. A thread on linux-gpio from June 2026 about this exact model identifies pin 4 as HDMI hotplug detect routed through the discrete GPU, and pin 2 as USB-C DisplayPort hotplug. Which fits: the external display blanking is the thing that triggers suspend, and the same display’s hotplug line is the thing that ends it.

The fix🔗

The kernel’s GPIO ACPI layer has a quirk table with ignore_wake entries for a handful of ASUS and Acer machines with the same controller. Nothing for this Lenovo, as of 7.1 and linux-next. But the same mechanism is exposed as a module parameter, so no patch is needed:

gpiolib_acpi.ignore_wake=AMDI0030:00@4

Added to the kernel command line and rebooted. The kernel confirms it at boot:

amd_gpio AMDI0030:00: Ignoring wakeup on pin 4

Since then pin 4 has fired zero times, and the machine has suspended ten times in four days, each time because someone meant it to.

One detail from the linux-gpio thread is worth recording for anyone on this model. The reporter there was on BIOS LPCN62WW, where the firmware did not declare pins 2 and 4 as ACPI event pins at all, so ignore_wake had nothing to match and they wrote an out-of-tree module instead. On LPCN65WW the firmware does declare them, they show up as “ACPI:Event” IRQs 26 and 27, and the plain parameter works. So the fix depends on the BIOS version. There is also a Fedora discussion covering the same pins.

Collateral damage🔗

Two thousand suspend cycles a day is not free. On one of those nights the internal USB hub (a Genesys Logic 05e3:0610) failed to resume, the kernel gave up on it with error -22 and disconnected it, and it took the built-in Realtek Bluetooth radio down with it. No Bluetooth until a full power-off. The webcam, on the same hub, was resetting on every single wake. If a machine that “sleeps fine” has flaky USB peripherals in the morning, it is worth counting how many times it actually slept.

A second, rarer wake source remains: the Logitech Bolt receiver supports USB remote wake and woke one of the test suspends. It is much less frequent, does not loop, and was left alone.

What I would do differently🔗

Check the suspend count before checking anything else. journalctl -u systemd-logind | grep -c Suspending on a machine that has been closed overnight should be a single-digit number. Everything downstream of that, the unit restarts, the Bluetooth loss, the webcam resets, was explained by one number that took two days to look at.