tb_dp_port_hpd_is_active(9)

📦 version 7.3.1, in nixpkgs unstable

💅 tb_dp_port_hpd_is_active — a Kernel API Manual moment

okay so bestie, welcome to the Kernel API Manual, section 9, and today's main character is tb_dp_port_hpd_is_active. she's a tiny little function with one job and honestly? she ate. 🫶

✨ NAME ✨

tb_dp_port_hpd_is_active — is HPD already active? that's it. that's the whole vibe check. 💅

🌸 SYNOPSIS 🌸

int tb_dp_port_hpd_is_active(struct tb_port *port);

like literally one arg, returns an int, no drama, no cap. ✨

🦋 ARGUMENTS 🦋

  • port — the DP out port you want to check 👀 (yes it's a struct tb_port *, yes you gotta pass a real one, iykyk)

🎀 DESCRIPTION 🎀

so what does she actually do? she checks whether the DP OUT adapter port already has the HPD bit set. that's the whole thing. that's the assignment and she understood it. 💖

no side quests, no surprises, just a lil peek at the HPD bit. iconic behavior honestly. ⭐

🔥 RETURN 🔥

  • 1 — HPD is active, she's UP, slay 💅
  • 0 — HPD is not active, that's the other outcome bestie 😭

like it's binary, it's giving simple, it's giving correct. periodt. ✨

ngl this is not a -1-on-error situation, the page literally just says 1 or 0, so don't go inventing extra return codes, okay? 🫶

🌈 SEE ALSO 🌈

first up, the kernel file this all lives in:

  • ./drivers/thunderbolt/switch.c

and then the whole extended friend group (they're all in section 9, they all said hi):

like look at that roster. whole friend group showed up. 💜

and that's the page bestie!! this lil icon lives under ./drivers/thunderbolt, dated October 2026 — so go forth and check that HPD bit, ily, bye 🧚💖✨

📦 where this page comes from