dm_test_scal...rder_changed(9)

💅 dm_test_scal...rder_changed(9) — the vibe check

okay so bestie, this page lives in the Kernel API Manual, and it's all about one little KUnit test whose full name is dm_test_scaling_state_underscan_border_changed. the header on the page is squished down to dm_test_scal...rder_changed(9) (yes, it got truncated, she's mysterious like that ✨), but the function herself is an absolute icon. let's get into it 🫶

---

✨ NAME ✨

dm_test_scaling_state_underscan_border_changed — literally tests that changed underscan borders actually differ. no cap, that's the whole assignment 🎀

---

🌸 SYNOPSIS 🌸

void dm_test_scaling_state_underscan_border_changed (struct kunit *test
);

that's it, that's the signature. short and slay 🔥

---

🦋 ARGUMENTS 🦋

• test — the KUnit test context 💖 this is the little context object the test hangs out in. you hand it over and she does her thing.

---

👑 SEE ALSO 👑

bestie, the cross-reference list here is long, and every single one of these is iconic in her own right. no skipping, we're reading the whole roster 🧚

the kernel file itself is right here:

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

and now the guest list 💜:

• dm_test_is_idle(9)
• dm_test_wait_for_idle(9)
• dm_test_soft_reset(9)
• dm_test_set_clockgating_state(9)
• dm_test_set_powergating_state(9)
• dm_test_bandwidth_update(9)
• dm_test_crtc_complete_writeback_no_connector(9)
• dm_test_crtc_complete_writeback_not_pending(9)
• dm_test_vblank_get_counter_out_of_range(9)
• dm_test_vblank_get_counter_no_stream(9)
• dm_test_crtc_get_scanoutpos_invalid_crtc(9)
• dm_test_crtc_get_scanoutpos_no_stream(9)
• dm_test_atomic_get_new_state_empty(9)
• dm_test_atomic_get_new_state_match(9)
• dm_test_atomic_destroy_state_no_context(9)
• dm_test_plane_layer_index_cmp_equal(9)
• dm_test_plane_layer_index_cmp_descending(9)
• dm_test_plane_layer_index_cmp_ascending(9)
• dm_test_fill_color_attr_rgb_format(9)
• dm_test_fill_color_attr_bt601_full(9)
• dm_test_fill_color_attr_bt601_limited(9)
• dm_test_fill_color_attr_bt709_full(9)
• dm_test_fill_color_attr_bt709_limited(9)
• dm_test_fill_color_attr_bt2020_full(9)
• dm_test_fill_color_attr_bt2020_limited(9)
• dm_test_fill_color_attr_invalid_encoding(9)
• dm_test_modereset_required_when_inactive_and_modeset(9)
• dm_test_modereset_not_required_when_active_and_modeset(9)
• dm_test_modereset_not_required_when_inactive_without_modeset(9)
• dm_test_scaling_state_same(9)
• dm_test_scaling_state_scaling_changed(9)
• dm_test_scaling_state_underscan_enabled(9)
• dm_test_scaling_state_underscan_disabled(9)
• dm_test_multisync_trigger_disabled(9)
• dm_test_multisync_trigger_rising(9)
• dm_test_multisync_trigger_falling(9)
• dm_test_master_stream_highest_refresh(9)
• dm_test_master_stream_defaults_to_first(9)
• dm_test_cp_diff_hdcp_type_change(9)
• dm_test_cp_diff_reenable_mode_changed(9)
• dm_test_cp_diff_reenable_no_change(9)
• dm_test_cp_diff_undesired(9)
• dm_test_cp_diff_desired_mode_changed(9)
• dm_test_cp_diff_desired_no_change(9)
• dm_test_cp_diff_update_hdcp_hotplug(9)
• dm_test_cp_diff_stream_reenabled(9)
• dm_test_cp_diff_s3_undesired_to_enabled(9)
• dm_test_cp_diff_desired_to_enabled(9)
• dm_test_cp_diff_desired_to_undesired(9)
• dm_test_per_frame_master_sync_single_stream(9)
• dm_test_per_frame_master_sync_two_streams(9)
• dm_test_per_frame_master_sync_skips_null_stream(9)
• dm_test_apply_delay_null_sink(9)
• dm_test_apply_delay_zero_wait(9)
• dm_test_apply_delay_nonzero_wait(9)

like… the whole friend group showed up. periodt 💅

---

quick little heads-up bestie: this page is dated October 2026 and her source path is ./drivers/gpu/drm/amd/display/... — so yeah, keep that in mind if you're citing her anywhere 🌈

and that's the page! go forth and test those underscan borders, you absolute main character 🦋✨💖