drm_dp_downs...x_tmds_clock(9)

📦 version 7.3.1, in nixpkgs unstable

💅 drm_dp_downstream_max_tmds_clock(9) 💅

okay so bestie, welcome to the kernel API manual — this one lives under the manual name drm_dp_downs...x_tmds_clock(9) (yes the header truncates it, that's just how the man page abbreviates long names, don't come for me 😭). This is a DisplayPort helper function and it's literally about figuring out the max TMDS clock of a downstream facing port. iconic already.

✨ NAME ✨

drm_dp_downstream_max_tmds_clock — extract downstream facing port max TMDS clock 🎀

🦋 SYNOPSIS 🦋

int drm_dp_downstream_max_tmds_clock (const u8
dpcd[DP_RECEIVER_CAP_SIZE] , const u8 port_cap[4] , const struct
drm_edid *drm_edid );

That's the whole signature, character for character, no cap. Three args, one int back. slay.

🌸 ARGUMENTS 🌸

  • dpcd — DisplayPort configuration data 💖 (you know, the DPCD blob)
  • port_cap — port capabilities (the port_cap[4] array, four whole bytes of it)
  • drm_edid — EDID ✨ (pointer to const struct drm_edid)

👑 RETURN 👑

It gives you the HDMI/DVI downstream facing port max TMDS clock in kHz on success 🎉 — or 0 if the max TMDS clock is not defined. that's it, that's the deal. if you get a zero, it's not an error, it just means "not defined," so don't panic 🫶

🔥 SEE ALSO 🔥

buckle up bestie, this list is long and it ate 💀 — the kernel file lives at ./drivers/gpu/drm/display/drm_dp_helper.c, and here's every single cross-reference, no skipping, periodt:

like, that's a whole friend group right there 🌈

reminder bestie: dp helpers(9) shows up twice in the original list (once folded in with the kernel file path line, once on its own), so it's here twice too. we don't erase references in this house 💅

and that's the page!! mwah 💖 this little beauty ships out of ./drivers/gpu/drm/display, dated October 2026 — go forth and read your DPCD, bestie, you got this 🧚‍♀️⭐🍓

📦 where this page comes from