drm_crtc_acc...vblank_count(9)

📦 version 7.3.1, in nixpkgs unstable

💖 drm_crtc_acc...vblank_count(9) 💖

okay so this is a page straight out of the Kernel API Manual, bestie — the whole title is drm_crtc_acc...vblank_count(9) (yes it's truncated, no I can't fix it, that's just how it's printed 💅). it's about counting vblanks accurately, and honestly? it ate.

✨ NAME ✨

drm_crtc_accurate_vblank_count — retrieve the master vblank counter 🎀

🌸 SYNOPSIS 🌸

u64 drm_crtc_accurate_vblank_count (struct drm_crtc *crtc );

🦋 ARGUMENTS 🦋

  • crtc — which counter to retrieve, babes. that's the whole vibe check right there ✨

💜 DESCRIPTION 💜

so this function is lowkey a cousin of drm_crtc_vblank_count — same energy, but this one interpolates to handle a race with vblank interrupts, using the high precision timestamping support. no cap, that's the whole flex 🔥

it's mostly useful for hardware that can obtain the scanout position but doesn't have a hardware frame counter. like, it's giving "i can see where we are but i can't count" and this function is the main character that steps in 🫶

ngl the interpolation is the entire point here — don't sleep on it.

🌈 SEE ALSO 🌈

the whole friend group 💖 (kernel file ./drivers/gpu/drm/drm_vblank.c, and yes, all of these):

okay that's the page!! 💅 this came from ./drivers/gpu/drm and it's dated October 2026 — periodt, go read the whole vblank saga, ily, bye 🎀✨💖

📦 where this page comes from