dm_mst_test...er_null_link(9)

🎀 NAME 🎀

dm_mst_test_pbn_divider_null_link — the KUnit test that's literally just "hey bestie, what happens if the link pointer is NULL" ✨

(oh and btw, this page lives in the Kernel API Manual, section 9 — iykyk 💅)

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🦋 SYNOPSIS 🦋

void dm_mst_test_pbn_divider_null_link (struct kunit *test );

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🌸 ARGUMENTS 🌸

• test — the KUnit test context, aka the little group chat this test is running inside 🫶

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✨ DESCRIPTION ✨

okay so here's the vibe: this test checks that dm_mst_get_pbn_divider comes back with 0 when you hand it a NULL link pointer — and, like, without crashing 💀

that's it. that's the whole test. it's giving "defensive coding icon" and honestly? we're obsessed 👑

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🌈 SEE ALSO 🌈

the kernel file it lives in, no cap:

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

and the whole friend group of sibling tests (all of them, fr fr, nobody gets left out):

• dm_mst_test_needs_dsc_aux_workaround_match(9)
• dm_mst_test_needs_dsc_aux_workaround_rev12(9)
• dm_mst_test_needs_dsc_aux_workaround_wrong_dev_id(9)
• dm_mst_test_needs_dsc_aux_workaround_wrong_rev(9)
• dm_mst_test_needs_dsc_aux_workaround_low_sink_count(9)
• dm_mst_test_needs_dsc_aux_workaround_zero_sink_count(9)
• dm_mst_test_pbn_divider_uses_link_bandwidth(9)
• dm_mst_test_reset_connector_setting(9)
• dm_mst_test_retrieve_downstream_no_aux(9)
• dm_mst_test_retrieve_downstream_present(9)
• dm_mst_test_retrieve_downstream_aux_error(9)
• dm_mst_test_retrieve_branch_no_parent(9)
• dm_mst_test_retrieve_branch_reads_oui(9)
• dm_mst_test_aux_result_success(9)
• dm_mst_test_aux_result_eio(9)
• dm_mst_test_aux_result_ebusy(9)
• dm_mst_test_aux_result_timeout(9)
• dm_mst_test_aux_transfer_native_read(9)
• dm_mst_test_aux_transfer_native_write(9)
• dm_mst_test_aux_transfer_partial_write(9)
• dm_mst_test_aux_transfer_error_result(9)
• dm_mst_test_aux_transfer_hpd_discon_quirk(9)
• dm_mst_test_aux_transfer_non_ack_reply(9)
• dm_mst_test_fill_payload_flags_native_write(9)
• dm_mst_test_fill_payload_flags_native_read(9)
• dm_mst_test_fill_payload_flags_i2c_read_mot(9)
• dm_mst_test_fill_payload_flags_write_status(9)
• dm_mst_test_msg_ready_mask(9)
• dm_mst_test_select_esi_dpcd_legacy(9)
• dm_mst_test_select_esi_dpcd_esi(9)
• dm_mst_test_sideband_msg_ready_no_ready_bits(9)
• dm_mst_test_sideband_msg_ready_read_error(9)
• dm_mst_test_sideband_msg_ready_without_mst_state(9)
• dm_mst_test_down_rep_msg_ready_wrapper(9)
• dm_mst_test_initialize_dp_connector_edp(9)
• dm_mst_test_initialize_dp_connector_mst(9)
• dm_mst_test_atomic_best_encoder(9)
• dm_mst_test_create_fake_mst_encoders(9)
• dm_mst_test_atomic_check_no_old_crtc(9)
• dm_mst_test_detect_unregistered(9)
• dm_mst_test_fp_guarded_public_stubs(9)

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💖 that's the whole page bestie, go read the source if you want the lore

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sign-off time 🫶 this one's straight outta ./drivers/gpu/drm/amd/display/... and it's dated October 2026 — slay, see you in the next manpage 💅✨