dm_test_pro...gine_acquire(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dm_test_pro...gine_acquire(9) — from the Kernel API Manual, bestie

okay so real talk, the title got cut off by the terminal gods (it's giving "my username when the text box is too small"), but the full name is dm_test_process_dmub_aux_transfer_sync_engine_acquire and yes she is a KUnit test, and yes she is iconic for what she does. let's get into it ✨

🌸 NAME 🌸

dm_test_process_dmub_aux_transfer_sync_engine_acquire — the test that checks what happens when the AUX transfer engine-acquire fails. like, it goes out of its way to make the acquire not work, which is lowkey the whole point 🎀

🦋 SYNOPSIS 🦋

void dm_test_process_dmub_aux_transfer_sync_engine_acquire (struct kunit
test );

that's it. one function, one argument, no return value. she's minimal, she's clean, she ate 💅

🍓 ARGUMENTS 🍓

  • test — the KUnit test context. that's the lil bubble of a world this test runs inside, basically. it's how KUnit knows who's who 🫶

👑 DESCRIPTION 👑

okay so here's the vibe. you know dc->link_count? they set it to 0 in this scenario — zero, nada, none of the links. and the way that dc_process_dmub_aux_transfer_async handles that is not cute: it straight up rejects the link index 💀

so then amdgpu_dm_process_dmub_aux_transfer_sync picks up the pieces, reports an engine-acquire error, and returns -1. that's the whole test. that's her. the acquire fails, the error gets reported, -1 comes back, and the test goes "yep, that's exactly what I expected" and passes 😭🔥

no cap, this is a failure-path test — the fact that things don't work is the successful outcome. main character energy honestly.

🌈 SEE ALSO 🌈

buckle up bestie, this is a whole friend group 🫶

like I said. huge friend group. every single one of them is a (9) and every single one of them said hi 👋

ngl there are a lot of them, but go read them all, bestie — they're all in that same kernel file and they're all doing the lord's work ✨

and that's the page, fr fr 🎀 this lil writeup came straight out of ./drivers/gpu/drm/amd/display/... and it's dated October 2026, so mark your calendar, mwah 💋🦋🌸

📦 where this page comes from