drm_gtf_mode(9)

📦 version 7.3.1, in nixpkgs unstable

💖 drm_gtf_mode(9) — Kernel API Manual 💖

okay bestie, welcome to the Kernel API Manual 💅 this one is all about drm_gtf_mode(9), and it's lowkey a whole modeline-making moment. let's get into it 🫶

✨ NAME ✨

drm_gtf_mode — create the modeline based on the GTF algorithm 🌸

✨ SYNOPSIS ✨

struct drm_display_mode * drm_gtf_mode (struct drm_device *dev , int
hdisplay , int vdisplay , int vrefresh , bool interlaced , int margins
);

✨ ARGUMENTS ✨

  • dev — drm device 🎀
  • hdisplay — hdisplay size ✨
  • vdisplay — vdisplay size 💖
  • vrefresh — vrefresh rate. ⭐
  • interlaced — whether to compute an interlaced mode 🦋
  • margins — desired margin (borders) size 🌸

✨ DESCRIPTION ✨

return the modeline based on GTF algorithm 💫

This function is to create the modeline based on the GTF algorithm. Generalized Timing Formula is derived from:

GTF Spreadsheet by Andy Morrish (1/5/97) available at https://www.vesa.org 📺

And it is copied from the file of xserver/hw/xfree86/modes/xf86gtf.c. What the author did is translate it by using integer calculation. They also refer to the function of fb_get_mode in the file of drivers/video/fbmon.c 🧚

🌈 Standard GTF parameters 🌈

M = 600
C = 40
K = 128
J = 20

✨ RETURN ✨

The modeline based on the GTF algorithm stored in a drm_display_mode object. The display mode object is allocated with drm_mode_create. Returns NULL when no mode could be allocated. 😭💖

✨ SEE ALSO ✨

Kernel file ./drivers/gpu/drm/drm_modes.c 👑

the whole SEE ALSO friend group is here, no cap:

xoxo, your Unix bestie 💅 this page comes from ./drivers/gpu/drm, dated October 2026, and the manual page is drm_gtf_mode(9) 🎀✨

📦 where this page comes from