hwspin_unlock_irqrestore(9)

📦 version 7.3.1, in nixpkgs unstable

💅 hwspin_unlock_irqrestore — Kernel API Manual, bestie edition ✨

okay so you're looking at hwspin_unlock_irqrestore(9) from the Kernel API Manual and honestly? she's the cleanup queen 👑 — the one you call when you've already grabbed your lock and you need to put everything back exactly how you found it. no cap.

🌸 NAME 🌸

hwspin_unlock_irqrestore — unlock hwspinlock, restore irq state 💖

✨ SYNOPSIS ✨

void hwspin_unlock_irqrestore (struct hwspinlock *hwlock , unsigned long
*flags );

like, that's the whole signature. two args. she's lowkey elegant 🎀

🦋 ARGUMENTS 🦋

  • hwlock — a previously-acquired hwspinlock which we want to unlock 🔓 this is the one you already grabbed, bestie, we're letting her go
  • flags — previous caller's interrupt state to restore 🫶 the interrupt state from whoever called us, handed back so we can put it right back where it belongs

💜 DESCRIPTION 💜

so what does she actually do? three things, and she does them all in one go, main character energy fr fr:

This function will unlock a specific hwspinlock, enable preemption and restore the previous state of the local interrupts. 🎀 It should be used to undo, e.g., hwspin_trylock_irqsave.

think of it as the undo button for hwspin_trylock_irqsave — you locked, you saved the irq state, and now you're reversing out of it. it's giving symmetry. it's giving closure. it's giving responsible kernel developer 💅

⚠️ okay real talk though — hwlock must be already locked before calling this function: it is a bug to call unlock on a hwlock that is already unlocked. not a vibe. not a slay. that's a bug, periodt. 💀 if you're out here unlocking something that was never locked, the kernel is gonna have opinions and none of them are cute.

🌈 SEE ALSO 🌈

Kernel file ./include/linux/hwspinlock.h 📁 — and the whole friend group, because she does not exist in a vacuum, iykyk:

🌸 cute sign-off time 🌸 — this lil page lives under ./include/linux, dated October 2026, and it's literally called hwspin_unlock_irqrestore(9). go lock responsibly, bestie. mwah 🫶💖✨

📦 where this page comes from