enable_irq(9)

✨ enable_irq — like, the Kernel API Manual energy ✨

okay bestie, we're in the enable_irq(9) girlies today 💅 this one's short and sweet, no cap.

---

🌸 NAME 🌸

enable_irq — enables the handling of an irq 🔥 (yes, that's the whole job, and she does it well)

---

🎀 SYNOPSIS 🎀

void enable_irq (unsigned int irq );

---

🦋 ARGUMENTS 🦋

• irq — the interrupt you wanna enable, periodt ✨

---

💖 DESCRIPTION 💖

So basically? This function undoes the effect of one single call to disable_irq. One call, one undo — they're matched, iykyk 🫶

And if this happens to match the last disable? That's when the processing of interrupts on this IRQ line gets re-enabled. slay. the gates are open again 💅✨

⚠️ okay important caveat bestie, don't skip this: this function may be called from IRQ context only when desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL ! Like, both of them. NULL. Otherwise? not the vibe, don't do it 😭

---

🌈 SEE ALSO 🌈

Kernel file ./kernel/irq/manage.c — and here's the whole friend group, literally all of them, no one left out 🫶:

• synchronize_hardirq(9)
• synchronize_irq(9)
• irq_can_set_affinity(9)
• irq_can_set_affinity_usr(9)
• irq_set_thread_affinity(9)
• irq_affinity_schedule_notify_work(9)
• irq_update_affinity_desc(9)
• irq_set_affinity(9)
• irq_force_affinity(9)
• irq_set_affinity_notifier(9)
• irq_set_vcpu_affinity(9)
• disable_irq_nosync(9)
• disable_irq(9)
• disable_hardirq(9)
• disable_nmi_nosync(9)
• enable_nmi(9)
• irq_set_irq_wake(9)
• irq_wake_thread(9)
• free_irq(9)
• request_threaded_irq(9)
• request_any_context_irq(9)
• request_nmi(9)
• irq_percpu_is_enabled(9)
• free_percpu_irq(9)
• request_percpu_irq_affinity(9)
• request_percpu_nmi(9)
• prepare_percpu_nmi(9)
• teardown_percpu_nmi(9)
• irq_get_irqchip_state(9)
• irq_set_irqchip_state(9)
• irq_has_action(9)
• irq_check_status_bit(9)

---

okay that's the whole page bestie, go turn some interrupts back on 💜

so yeah — this drop lives under ./kernel/irq and it's dated October 2026, brought to you by the enable_irq(9) girlies themselves 🧚‍♀️ mwah, bye 🎀