for_each_ol...rtc_in_state(9)

📦 version 7.3.1, in nixpkgs unstable

💅 for_each_ol...rtc_in_state(9) — like, the Kernel API Manual one, bestie ✨

Okay so picture this: you're deep in the kernel docs (the Kernel API Manual, to be exact) and you stumble on for_each_oldnew_crtc_in_state. It's a macro. It's iconic. It's giving "I loop so you don't have to." Let's get into it 🎀

✨ NAME ✨

for_each_oldnew_crtc_in_state — the macro that iterates over all CRTCs in an atomic update 🦋

🌸 SYNOPSIS 🌸

for_each_oldnew_crtc_in_state (__state , crtc , old_crtc_state ,
new_crtc_state , __i );

🎀 ARGUMENTS 🎀

  • __state — a struct drm_atomic_commit pointer. Yep, the whole commit, the main character 👑
  • crtc — a struct drm_crtc iteration cursor. It's your little walking pointer through the loop 💫
  • old_crtc_state — a struct drm_crtc_state iteration cursor, but for the old state. The before pics 📸
  • new_crtc_state — a struct drm_crtc_state iteration cursor, but for the new state. The glow-up ✨
  • __i — an int iteration cursor, strictly for macro-internal use. Don't touch, don't look at it, it's doing its job 🙈

💖 DESCRIPTION 💖

So this macro iterates over all the CRTCs in an atomic update, and — here's the slay — it tracks both the old state and the new state at the same time. Two cursors, one loop, zero drama 💅

Where is that even useful? Anywhere the state delta actually matters, lowkey. Like, for example, in atomic check functions. That's the vibe. That's the whole point. Periodt 🫶

🦋 SEE ALSO 🦋

The kernel file ./include/drm/drm_atomic.h and honestly a whole friend group of related stuff — no cap, here's every single one 💜

Bestie reminder: __i is macro-internal. Do not pass your own thing in there, do not get cute with it, just let the macro cook 🍓

And that's the whole page, mwah 💋 signin' off from ./include/drm — that's the source, and the date on this baddie is October 2026, and it's all filed under for_each_ol...rtc_in_state(9). Slay, go read your kernel headers 🌈⭐

📦 where this page comes from