dm_test_wb_..._check_no_fb(9)

💅 dm_test_wb_..._check_no_fb(9) 💅

okay so welcome to the Kernel API Manual bestie, we're looking at dm_test_wb_..._check_no_fb(9) today and honestly? it's a lil icon. it ate. let's get into it 🎀

---

✨ NAME ✨

dm_test_wb_atomic_check_no_fb — the test that verifies the function makes an early return when the job has no framebuffer. literally the vibe check for the no-fb case 🦋

---

🌸 SYNOPSIS 🌸

void dm_test_wb_atomic_check_no_fb (struct kunit *test );

---

🎀 ARGUMENTS 🎀

• test — the KUnit test context. yeah that's it, that's the whole argument, she's low maintenance bestie 💅

---

👑 DESCRIPTION 👑

okay so picture this: a writeback job exists, right, it's there, it's real — but job->fb is <rainbow>NULL</rainbow> 😭 and when that happens, the function should just return 0 and not go off validating dimensions or pixel format. like, there's nothing to validate, why would she even try? she doesn't. she returns 0. main character energy fr fr ✨

no cap: no framebuffer means no dimension check and no pixel format check. early return only. periodt 🫶

---

💖 SEE ALSO 💖

Kernel file

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

and the whole bestie squad of related tests, all iconic, all here:

• dm_test_wb_atomic_check_no_job(9)
• dm_test_wb_atomic_check_valid(9)
• dm_test_wb_atomic_check_size_mismatch(9)
• dm_test_wb_atomic_check_width_mismatch(9)
• dm_test_wb_atomic_check_height_mismatch(9)
• dm_test_wb_atomic_check_invalid_format(9)
• dm_test_wb_get_modes_returns_modes(9)
• dm_test_wb_get_modes_bounded_by_max(9)
• dm_test_wb_connector_init_success(9)
• dm_test_wb_prepare_job_no_fb(9)
• dm_test_wb_cleanup_job_no_fb(9)

---

🌈✨ and that's the page!! quick lil sign-off before you go: this one lives under ./drivers/gpu/drm/amd/display/..., dated October 2026, and it's giving very much "short page, big slay" 💜 go read the other dm_test_wb_* pages, ily, bye 🍓🧚