acpi_dev_found(9)

📦 version 7.3.1, in nixpkgs unstable

✨ acpi_dev_found ✨

okay so bestie, welcome to the kernel API manual 💅 this one's a little cutie from the ACPI corner of the kernel, and honestly it's giving "is my device even here rn" energy. let's get into it 🫶

🌸 NAME 🌸

acpi_dev_found — bestie's whole job is detecting whether a given ACPI device is actually present in the namespace. that's it, that's the vibe check 🔍✨

🦋 SYNOPSIS 🦋

bool acpi_dev_found (const char *hid );

🎀 ARGUMENTS 🎀

  • hid — the Hardware ID of the device 💖 like, the lil name tag your device is wearing so we know which one we're looking for.

💜 DESCRIPTION 💜

so this function returns true if the device was present at the moment of invocation. at the moment, bestie — that's the key phrase 👀 note that if the device is pluggable, it may since have disappeared. so like, it could've dipped between you asking and you doing anything about it. tragic, but that's the deal 😭

🚨 for this function to actually work, acpi_bus_scan must have been executed — and that happens in the subsys_initcall subsection. so do not call it from a subsys_initcall or earlier (use acpi_get_devices instead, okay? 💀). calling from module_init is totally fine, and that's synonymous with device_initcall ✨

so like, timing is everything here. call too early and it's not gonna slay, it's just gonna fail. respect the init order, periodt 👑

🌈 SEE ALSO 🌈

kernel file ./drivers/acpi/utils.c, plus the whole friend group of related functions — go say hi 💖:

and that's the whole page, bestie, no cap 🎀 this lil icon lives in ./drivers/acpi and the docs are dated October 2026 — go forth and detect those devices, ily, bye 💅✨🦋

📦 where this page comes from