ntb_link_is_up(9)

📦 version 7.3.1, in nixpkgs unstable

okay so bestie, welcome to the Kernel API Manual — section 9, main character energy only. today's episode: ntb_link_is_up ✨

🌸 NAME 🌸

ntb_link_is_up — get the current ntb link state. that's it. that's the whole vibe check 🔥

🎀 SYNOPSIS 🎀

u64 ntb_link_is_up (struct ntb_dev *ntb , enum ntb_speed *speed , enum
ntb_width *width );

literally one function, three args, and it tells you whether the link is up. no cap 💅

🦋 ARGUMENTS 🦋

  • ntb — NTB device context. the little context handoff, yk? you know exactly whose link we're asking about.
  • speed — OUT — The link speed expressed as PCIe generation number. it's an out param bestie, you're not telling it anything, it's telling you 👑
  • width — OUT — The link width expressed as the number of PCIe lanes. also out. also giving data. both of these fill in your values for you, so slay.

✨ DESCRIPTION ✨

Get the current state of the ntb link. that's the mission. that's the assignment. 🫶

It is recommended to query the link state once after every link event. once. not in a loop, not on repeat, not spam-calling it like it's a crush's instagram — once, after each link event. 💀

It is safe to query the link state in the context of the link event callback. so yes, you can call it right there inside the callback, no anxiety, no "am I allowed to be here" moment. you are literally invited. 🌈

⭐ RETURN ⭐

bitfield of indexed ports link state: bit is set/cleared if the link is up/down respectively.

translation for the group chat: it hands you back a u64, and each indexed port gets a bit. link up? bit set. link down? bit cleared. one bit per port, no cap 💖

👑 SEE ALSO 👑

Kernel file ./include/linux/ntb.h — and here comes the friend group, the whole squad, the entire NTB roster, we love a full roster bestie:

like I said. the whole squad. ate and left no crumbs 🍓

okay that's the page bestie, go read your link state responsibly 💜

sign-off szn: this icon lives in ./include/linux, dated October 2026, and it's called ntb_link_is_up(9) — mwah, bye 🧚‍♀️💅

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