dm_test_dmub..._no_dmub_srv(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dm_test_dmub..._no_dmub_srv(9) — from the Kernel API Manual, bestie 🎀

okay so this is a kernel API manpage, and yes the name is a whole mouthful (dm_test_dmub..._no_dmub_srv(9)) but don't panic — it's lowkey just one KUnit test, and it's kind of an icon actually. sit down, grab a lil snack 🍓, and let's get into it.

✨ NAME ✨

dm_test_dmub_hw_init_no_dmub_srv — the test that checks hw init returns 0 when DMUB isn't supported. she's doing her job and doing it well 💅

🦋 SYNOPSIS 🦋

void dm_test_dmub_hw_init_no_dmub_srv (struct kunit *test );

that's it. that's the whole signature. short and slay ✨

🌸 ARGUMENTS 🌸

  • test — the KUnit test context. it's the little container that holds all the test-y stuff, and our function just takes it and vibes with it 🫶

👑 DESCRIPTION 👑

okay so the whole plot twist here: when adev->dm.dmub_srv is NULL, that means the ASIC straight up does not support DMUB. no cap.

and in that case, dm_dmub_hw_init should return 0 — and here's the important part — without touching the hardware. like, at all. not even a little poke. 🚫🖐️

so this test exists to make sure that when there's no DMUB server, the init path just politely returns success and keeps its hands to itself. iconic behaviour honestly 💀✨

🔥 SEE ALSO 🔥

first up, the actual kernel file where the magic lives:

  • Kernel file ./drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c

and then, bestie, the entire friend group — the whole test fam, all of them, no skips:

like I said. the whole fam. iykyk 💜

aaaand that's the page!! 🎀 this lil gem comes to you from ./drivers/gpu/drm/amd/display/..., dated October 2026 — so go forth, run that test, and remember: when dmub_srv is NULL, we do not touch the hardware. periodt. 💅🌟

📦 where this page comes from