devm_request_threaded_irq(9)

🎀 devm_request_threaded_irq(9) — from the Kernel API Manual 💅

okay bestie, buckle up, because this is the page you'll be pulling up every single time you wire an interrupt into a driver. this is devm_request_threaded_irq(9) (yes, the (9) means kernel API manual section, iykyk ✨) and it's the managed-device glow-up of the classic interrupt request — it allocates an interrupt line for a managed device and logs errors for you. main character energy fr fr 🫶

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✨ SYNOPSIS ✨

int devm_request_threaded_irq (struct device *dev , unsigned int irq ,
irq_handler_t handler , irq_handler_t thread_fn , unsigned long irqflags
, const char *devname , void *dev_id );

that's the whole vibe. seven arguments, one int back, no cap 👑

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🌸 ARGUMENTS 🌸

• dev — the device you're requesting the interrupt for. this is the extra one that makes it managed 🧚
• irq — the interrupt line you wanna allocate.
• handler — the function that gets called when the interrupt occurs. your first responder 💅
• thread_fn — the function called in a threaded interrupt context. pass NULL for devices that handle absolutely everything inside handler (some devices just don't need the thread, and that's valid 🌈).
• irqflags — the interrupt type flags.
• devname — an ascii name for the claiming device. if you pass NULL, it falls back to dev_name(dev) 🎀
• dev_id — a cookie that gets passed back to the handler function. yes, literally a cookie 🍓

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💖 DESCRIPTION 💖

so here's the tea: except for that extra dev argument, this function takes the same arguments and performs the same function as request_threaded_irq. (love a consistent API, honestly.) 🌸

the big deal, the reason you're here:

Interrupts requested with this function will be automatically freed on driver detach.

no manual cleanup, no forgetting, no 3am bug hunt. it's giving responsible adult energy 👑

but — and hear me out — if an interrupt allocated with this function ever needs to be freed separately, you must use devm_free_irq. don't get creative, bestie 🙈

and the part everyone skips: when the request fails, an error message is already printed with all the contextual info — device name, interrupt number, handler functions, and the error code. so don't add extra error messages at the call sites. it's already handled. it ate. let it cook 💀

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⭐ RETURN ⭐

0 on success, or a negative error number. that's it, that's the whole personality.

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🦋 SEE ALSO 🦋

kernel file ./kernel/irq/devres.c — that's where the magic lives, go read it 💜

• devm_request_any_context_irq(9)
• devm_free_irq(9)
• __devm_irq_alloc_descs(9)
• devm_irq_alloc_generic_chip(9)
• devm_irq_setup_generic_chip(9)
• devm_irq_domain_instantiate(9)

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and that's the page!! 🫶 sign-off time: this cutie lives in ./kernel/irq, dated October 2026, and its whole name in the manual is devm_request_threaded_irq(9) — remember it, cite it, love it 💖✨🎀