dm_test_coun...planes_mixed(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dm_test_coun...planes_mixed — Kernel API Manual ✨

okay bestie, welcome to the group chat. this one is a KUnit test from the kernel — yes, that kernel — and it's giving "small test, big responsibility" energy. the manual name is Kernel API Manual, and the page you're reading is dm_test_coun...planes_mixed(9). the title got truncated by the manpage formatter, not by me, so don't come for me 🫶

✨ NAME ✨

dm_test_count_crtc_active_planes_mixed — a test that counts across all the plane cases, no cap 💅

🌸 SYNOPSIS 🌸

void dm_test_count_crtc_active_planes_mixed (struct kunit *test );

🎀 ARGUMENTS 🎀

  • test — the KUnit test context. it's the little backpack this test carries around, literally.

🦋 DESCRIPTION 🦋

so what does this bad boy actually do? it exercises every branch of the counting loop. like, every single one. it's thorough like that 👑

here's the vibe check on the cases it hits:

  • a plane that's excluded by the mask — not invited to the party
  • a cursor plane — skipped entirely, sorry girl
  • a masked plane with no new state — counted ✅
  • a masked plane with a framebuffer — counted ✅
  • a masked plane without a framebuffer — not counted ❌

and after all that? only two planes should be reported active. that's the whole flex. two. not three, not one. two. periodt.

🔥 SEE ALSO 🔥

the kernel file lives here, bestie:

./drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_crtc_test.c

and here's the whole friend group — every single one of them, in the order the manpage gave them:

ngl the vibe of this list is "we tested literally everything so the DRM folks can sleep at night" and honestly? iconic of them 💜

anyway bestie, that's the page 🌈 — sourced from ./drivers/gpu/drm/amd/display/... and dated October 2026, closing out with the same truncated title you started with: dm_test_coun...planes_mixed(9). mwah, go count some planes 🍓🧚

📦 where this page comes from