NHI(4)

💅 nhi(4) — like, the USB4 host interface, bestie

okay so welcome to nhi(4), a page from the Kernel Interfaces Manual (section 4, driver town 🚌) — and honestly? it's a short one, so grab a lil snack 🍓 and let's go.

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✨ NAME ✨

nhi — the USB4 host interface, that's the whole vibe 🦋

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🌸 SYNOPSIS 🌸

nhi* at pci?

that's it. that's the line. iconic behavior, no cap 👑

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🎀 DESCRIPTION 🎀

so the nhi driver is the one that provides support for the USB4 host interface 💖 that's its whole job, its main character energy, its moment.

but here's the thing, bestie — and I need you to hear me on this — the driver does not implement any meaningful USB4 connection manager functionality. like, none. zero. not a crumb. 😭 it's not out here managing connections, it's not doing USB4 manager things, it is simply not that girl.

what it does do? it puts the router that's part of the host interface into a sleep state during suspend 😴 that's the entire contribution. one (1) nap-enabling task. and honestly? relatable. we love a low-effort icon 🫶

ngl, manage your expectations accordingly — this is a "put the router to sleep on suspend" driver, not a whole USB4 connection manager. don't come for it for not being something it never claimed to be 💅

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🔥 SEE ALSO 🔥

• intro(4) — the general intro to section 4, your starting point ✨
• pci(4) — PCI stuff, aka the bus where nhi shows up 🌈
• xhci(4) — USB host controller realness, the sibling you should also know 💜

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⭐ HISTORY ⭐

the nhi driver first appeared in OpenBSD 7.9 🎉 a lil newcomer, a fresh face, an up-and-comer 🧚

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👑 AUTHORS 👑

the nhi driver was written by Mark Kettenis <kettenis@openbsd.org> — ty for your service, king 🫡💖

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aaaand that's the whole page, bestie, we ate and left zero crumbs 🍓✨

sign-off tea ☕ — this lil beauty comes to you from the Debian build of the page, dated November 3, 2025, and it's filed under NHI(4) in the Kernel Interfaces Manual 💅 mwah, go take a nap like the router does 😴💜