dpm_watchdog_handler(9)

💅 dpm_watchdog_handler(9) — the kernel API manual, but make it make sense

okay so bestie, welcome to dpm_watchdog_handler(9), a page from the Kernel API Manual. yes that manual. the one with all the power-management lore. let's get into it 🫶

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✨ NAME ✨

dpm_watchdog_handler — the driver suspend / resume watchdog handler, aka the designated panic button when your driver ghosts the power management subsystem 💀

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🌸 SYNOPSIS 🌸

void dpm_watchdog_handler (struct timer_list *t );

that's it. one arg. returns nothing. slays quietly (until it doesn't).

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🎀 ARGUMENTS 🎀

• t — the timer that PM watchdog depends on ✨ literally the timer struct the whole power-management watchdog situation is running on.

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🔥 DESCRIPTION 🔥

so bestie. this function gets called when a driver has timed out suspending or resuming. like, the driver was supposed to go to sleep (or wake up) and it just… didn't. it's giving stuck. it's giving not responding. main character energy of the worst kind 😭

and here's the thing — there's not much we can do here to recover. like, at all. the situation is lowkey already a mess. so the move is to panic to capture a crash-dump in pstore. periodt. that's the entire strategy. we panic so the evidence survives 💅

no cap: this is a panic on purpose. it is not a recovery routine. do not expect it to save your driver, it's there to document the crime scene.

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👑 SEE ALSO 👑

the entire extended friend group, all from the kernel file ./drivers/base/power/main.c:

• pm_hibernate_is_recovering(9)
• device_pm_sleep_init(9)
• device_pm_lock(9)
• device_pm_unlock(9)
• device_pm_add(9)
• device_pm_remove(9)
• device_pm_move_before(9)
• device_pm_move_after(9)
• device_pm_move_last(9)
• dpm_wait(9)
• pm_op(9)
• pm_late_early_op(9)
• pm_noirq_op(9)
• dpm_watchdog_set(9)
• dpm_watchdog_clear(9)
• dev_pm_skip_resume(9)
• device_resume_noirq(9)
• dpm_resume_noirq(9)
• device_resume_early(9)
• dpm_resume_early(9)
• dpm_resume_start(9)
• device_resume(9)
• dpm_resume(9)
• device_complete(9)
• dpm_complete(9)
• dpm_resume_end(9)
• resume_event(9)
• device_suspend_noirq(9)
• dpm_suspend_noirq(9)
• device_suspend_late(9)
• dpm_suspend_late(9)
• dpm_suspend_end(9)
• legacy_suspend(9)
• device_suspend(9)
• dpm_suspend(9)
• device_prepare(9)
• dpm_prepare(9)
• dpm_suspend_start(9)
• device_pm_wait_for_dev(9)
• dpm_for_each_dev(9)

forty whole friends. a whole group chat. go read them if you want the full suspend/resume cinematic universe 🌈

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and that's the page, bestie 🦋 this one lives under ./drivers/base/power and it's dated October 2026 — so yeah, future-flavored documentation, iconic behavior honestly. mwah, go forth and don't let your driver time out 💖