dm_test_mst...c_part2_fail(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dm_test_mst...c_part2_fail(9) — bestie edition 🎀

okay so picture this: it's a page straight out of the Kernel API Manual, and the star of the show is literally dm_test_mst...c_part2_fail(9). yes that name is a whole mouthful, no i will not be shortening it, and yes it ate. let's get into it 🦋

✨ NAME ✨

dm_test_mst_send_payload_alloc_part2_fail — the icon, the moment, the legend: it exercises the failure branch 💀 (on purpose!! that's the whole point!!)

🌸 SYNOPSIS 🌸

void dm_test_mst_send_payload_alloc_part2_fail (struct kunit *test );

like... that's it. that's the whole function. she's void, she takes one arg, she does her little job and leaves. periodt 💅

🫶 ARGUMENTS 🫶

  • test — the KUnit test context, aka the VIP pass she needs to actually run. hand her one or she's not doing anything, fr fr 🎟️

👑 DESCRIPTION 👑

okay so here's the tea ☕ — this one builds a minimal MST topology-state fixture so the helper makes it past all those early NULL checks and actually gets to call drm_dp_add_payload_part2. we love a helper that reaches the interesting part 🌈

and here's the iconic bit: the payload's allocation status is left at its default — which, crucial detail, is not DRM_DP_MST_PAYLOAD_ALLOCATION_DFP. so because of that, drm_dp_add_payload_part2 returns -EIO 💀 and it does it without any remote DPCD/AUX traffic. no wire, no chatter, no nothing. quiet queen behavior 🙈

then that non-zero return value drives the failure branch, which clears the MST_ALLOCATE_NEW_PAYLOAD status bit. so yeah — the test is literally built to make things fail, and that's the point. failure branch gets its moment in the spotlight 🔥

ngl, a test whose entire purpose is to fail is peak main character energy. it's giving "i'm not broken, i'm testing" 💖

🦋 SEE ALSO 🦋

the whole extended friend group, in all their glory:

that's the whole thing, bestie, no notes 💜

and before you go — this lil page lives at ./drivers/gpu/drm/amd/display/... and it's dated October 2026, so like… future icon behavior honestly ⭐ mwah, go run your tests 🧚‍♀️💖

📦 where this page comes from