dm_test_dmub...o_hw_support(9)

💖 NAME 💖

okay so this is dm_test_dmub...o_hw_support(9) from the Kernel API Manual, and it's literally the test that checks what happens when the DMUB service shows up like "bestie i have no hardware support for you" 🫶

The name is longer than my attention span so let's spell it out: dm_test_dmub_hw_init_no_hw_support — Test hw init returns 0 when HW is unsupported. No cap, that's the whole vibe.

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✨ SYNOPSIS ✨

void dm_test_dmub_hw_init_no_hw_support (struct kunit *test );

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🎀 ARGUMENTS 🎀

• test — the KUnit test context, aka the little main-character passport every KUnit test carries around 💅

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🦋 DESCRIPTION 🦋

so picture this: the DMUB service is like "sorry babe, there's literally no hardware support here" 😭 and in that exact moment, dm_dmub_hw_init is supposed to do two iconic things:

1. log it — yes, leave a lil paper trail, we love receipts 📝
2. return 0 — and it does not go initializing any DMUB hardware, because there is none, periodt ✋

that's the whole test. no hardware, no init, just a log and a clean 0. slay.

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🌸 SEE ALSO 🌸

the whole friend group, all of them in (9), all of them here 💜

• Kernel file: ./drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c
• dm_test_register_dmub_notify_callback_null_callback(9)
• dm_test_register_dmub_notify_callback_type_out_of_range(9)
• dm_test_register_dmub_notify_callback_valid(9)
• dm_test_register_dmub_notify_callback_offload_false(9)
• dm_test_dmub_aux_setconfig_callback_copies_and_completes(9)
• dm_test_dmub_aux_setconfig_callback_non_aux_no_complete(9)
• dm_test_dmub_aux_setconfig_callback_aux_with_null_dm_notify(9)
• dm_test_dmub_aux_setconfig_callback_set_config_reply(9)
• dm_test_dmub_aux_fused_io_callback_copies_reply_and_completes(9)
• dm_test_dmub_aux_fused_io_callback_max_ddc_line(9)
• dm_test_dmub_aux_fused_io_callback_null_args(9)
• dm_test_get_default_ips_mode_dcn35(9)
• dm_test_get_default_ips_mode_dcn351(9)
• dm_test_get_default_ips_mode_dcn36(9)
• dm_test_get_default_ips_mode_older_than_dcn35(9)
• dm_test_get_default_ips_mode_newer_default(9)
• dm_test_dmub_hw_init_no_dmub_srv(9)
• dm_test_dmub_hw_init_no_fb_info(9)
• dm_test_dmub_hw_init_no_firmware(9)
• dm_test_dmub_hw_init_success_fake_dmub(9)
• dm_test_dmub_hw_init_bss_data(9)
• dm_test_dmub_hw_init_hw_init_fails(9)
• dm_test_dmub_hw_init_auto_load_timeout(9)
• dm_test_dmub_hw_init_apu_dpia_dcn35(9)
• dm_test_dmub_hw_init_sanity_checks_dcn31(9)
• dm_test_dmub_hw_init_sanity_checks_dcn314(9)
• dm_test_dmub_hw_init_dmcu_abm(9)
• dm_test_dmub_hw_resume_no_dmub_srv(9)
• dm_test_dmub_hw_resume_initialized_dmub(9)
• dm_test_dmub_hw_resume_full_init(9)
• dm_test_dmub_hw_resume_init_check_failed(9)
• dm_test_dmub_hw_resume_auto_load_timeout(9)
• dm_test_dmub_sw_init_unsupported_asic(9)
• dm_test_init_microcode_unsupported_asic(9)
• dm_test_dmub_get_vbios_bounding_box_default_null(9)
• dm_test_execute_dmub_cmd_null_dmub_srv(9)
• dm_test_process_dmub_aux_transfer_sync_engine_acquire(9)
• dm_test_process_dmub_aux_transfer_sync_protocol_error(9)
• dm_test_process_dmub_aux_transfer_sync_copies_data(9)
• dm_test_process_dmub_aux_transfer_sync_zero_length(9)
• dm_test_process_dmub_set_config_sync_unknown_error(9)
• dm_test_abort_fused_io_no_dmub_srv(9)

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fr fr go read the test file, it's giving lore 👑

and that's the whole page bestie 🎀 source incoming from ./drivers/gpu/drm/amd/display/... and the date stamp says October 2026 — mwah, bye 💋