drm_dp_read_downstream_info(9)

📦 version 7.3.1, in nixpkgs unstable

💅 drm_dp_read_downstream_info(9) — the Kernel API Manual, bestie edition ✨

Okay so welcome to the Kernel API Manual page for drm_dp_read_downstream_info(9), and no, that's not a typo, that's genuinely the whole function name and yes we're gonna get through it together 🫶

🌸 NAME 🌸

drm_dp_read_downstream_info — it reads the DPCD downstream port info if that info is even available, no cap 💖

⭐ SYNOPSIS ⭐

int drm_dp_read_downstream_info (struct drm_dp_aux *aux , const u8
dpcd[DP_RECEIVER_CAP_SIZE] , u8
downstream_ports[DP_MAX_DOWNSTREAM_PORTS] );

like, three args, one int coming back, that's the whole vibe 😌

🎀 ARGUMENTS 🎀

  • aux — the DisplayPort AUX channel. this is our little communication line, main character energy tbh 🦋
  • dpcd — a cached copy of the port's DPCD. cached!! we are NOT re-reading the world for this 💅
  • downstream_ports — the buffer where the downstream port info gets stored. it's the container, it's the vessel, it holds the goods 🍓

✨ DESCRIPTION ✨

See also: drm_dp_downstream_max_clock drm_dp_downstream_max_bpc

that's it. that's the description. short and iconic, honestly 👑

💜 RETURN 💜

You get 0 if the downstream port info was read successfully or if there was literally no downstream info to read (both count as a slay), or a negative error code otherwise 😭

🔥 SEE ALSO 🔥

Kernel file ./drivers/gpu/drm/display/drm_dp_helper.c

dp helpers(9) friends, assemble:

like genuinely the whole friend group showed up to this party 😭💀

and that's the page!! 🧚

cute little sign-off: this one lives in ./drivers/gpu/drm/display, it's dated October 2026, and the manual tag on the door says drm_dp_read_downstream_info(9). mwah 💋🌸
📦 where this page comes from