drm_dp_tunnel_available_bw(9)

📦 version 7.3.1, in nixpkgs unstable

💖 drm_dp_tunnel_available_bw(9) — the "how much bandwidth do we actually have" girlie 💖

okay so bestie, welcome to the Kernel API Manual ✨ this one lives in section 9 and honestly it's giving "small function, big feelings" 🎀

🌸 NAME 🌸

drm_dp_tunnel_available_bw — query the estimated total available BW of the tunnel 🦋

like, "hey tunnel, how much room do you got?" energy. periodt.

✨ SYNOPSIS ✨

int drm_dp_tunnel_available_bw (const struct drm_dp_tunnel *tunnel );

🫶 ARGUMENTS 🫶

  • tunnel — the tunnel object 💅 like, the actual tunnel we're asking about. that's her. that's the main character.

👑 DESCRIPTION 👑

So this function is literally here to query the estimated total available BW of the tunnel. and when we say "total," we mean it — it includes the currently allocated BW and the free BW for all the tunnels in tunnel's group 🔥 no gatekeeping, no hidden fees, we're counting everybody's bag.

⚠️ but bestie, the available BW is valid only after the BW allocation mode has been enabled for the tunnel and its state got updated by calling drm_dp_tunnel_update_state. skip either of those and the number is giving nothing. 💀

It returns the tunnel group's estimated total available bandwidth in kB/s units ⭐ or -1 if the available BW isn't valid — which happens when the BW allocation mode is not enabled, or when the tunnel's state hasn't been updated 🙈

so yeah: cute little int, tiny little units label, one (1) -1 for the vibes-not-valid situation.

🦋 SEE ALSO 🦋

Kernel file ./drivers/gpu/drm/display/drm_dp_tunnel.c 🧚

and the whole tunnel friend group, no cap:

okay that's the whole page, you ate that 💜 this one shipped from ./drivers/gpu/drm/display, dated October 2026 — and that's the tea, bestie, ily, go query your BW 🌈💖

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