dm_test_fil...ler_ycbcr420(9)

🎀 dm_test_fil...ler_ycbcr420(9) 🎀

okay so bestie, welcome to the Kernel API Manual — this is the page for dm_test_fil...ler_ycbcr420(9) and honestly it's a whole little vibe. let's get into it 💅

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✨ NAME ✨

dm_test_fill_stream_encoding_from_caller_ycbcr420 — the test for caller-selected 420, periodt. 🦋

✨ SYNOPSIS ✨

void dm_test_fill_stream_encoding_from_caller_ycbcr420 (struct kunit
*test );

✨ ARGUMENTS ✨

• test — the KUnit test context 🧚 that's it, that's the whole argument list, she's lowkey minimal

✨ DESCRIPTION ✨

okay so here's the tea ☕ — this helper no longer derives the pixel encoding from the display info. like, that era is over. instead, it applies whatever the caller selected. caller says jump, the helper says how high 💖

and the main character moment here: passing YCbCr420 must be honoured — even though the DisplayPort sink advertises no YCbCr color formats. yeah. the sink is out here claiming it doesn't support YCbCr at all, and the helper still has to respect the caller's choice. no cap, that's the entire point of the test 🔥

so like, if you were wondering "will it fall back to something sensible when the sink says no?" — nope! the caller picked 420, so it's 420. the display info doesn't get a vote. 👑

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<span>more parts coming bestie, don't go anywhere 🫶</span>

✨ SEE ALSO ✨

ok so before you go, bestie, here's the whole group chat — every single tester that lives next door to this one 💖

The kernel file these all hang out in is literally this one right here:

• ./drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c

and now the roll call, no cap, everyone's invited 🫶

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🦋 the subconnector type girlies

• dm_test_subconnector_type_none
• dm_test_subconnector_type_vga
• dm_test_subconnector_type_dvi_converter
• dm_test_subconnector_type_dvi_dongle
• dm_test_subconnector_type_hdmi_converter
• dm_test_subconnector_type_hdmi_dongle
• dm_test_subconnector_type_mismatched
• dm_test_subconnector_type_default_unknown

🎀 content type era

• dm_test_content_type_no_data
• dm_test_content_type_graphics
• dm_test_content_type_photo
• dm_test_content_type_cinema
• dm_test_content_type_game
• dm_test_content_type_unknown_defaults_no_data

💅 adjust colour depth, the glow-up arc

• dm_test_adjust_colour_depth_fits_at_888
• dm_test_adjust_colour_depth_reduces_to_888
• dm_test_adjust_colour_depth_10bpc_passes
• dm_test_adjust_colour_depth_420_halves_clk
• dm_test_adjust_colour_depth_420_reduces
• dm_test_adjust_colour_depth_reduces_12bpc_to_10bpc
• dm_test_adjust_colour_depth_16bpc_no_fallback
• dm_test_adjust_colour_depth_none_fits
• dm_test_adjust_colour_depth_invalid_depth

🌈 output color space (the whole rainbow, literally)

• dm_test_output_color_space_default_rgb_full
• dm_test_output_color_space_default_rgb_limited
• dm_test_output_color_space_default_ycbcr709
• dm_test_output_color_space_default_ycbcr601_limited
• dm_test_output_color_space_bt601_y_only
• dm_test_output_color_space_bt601
• dm_test_output_color_space_bt709
• dm_test_output_color_space_bt709_y_only
• dm_test_output_color_space_oprgb
• dm_test_output_color_space_bt2020_rgb
• dm_test_output_color_space_bt2020_rgb_limited
• dm_test_output_color_space_default_rgb_auto_hdmi_cta
• dm_test_output_color_space_default_rgb_auto_hdmi_vga
• dm_test_output_color_space_default_rgb_auto_dp_cta
• dm_test_output_color_space_default_rgb_full_hdmi_cta
• dm_test_output_color_space_bt2020_rgb_auto_hdmi_cta
• dm_test_output_color_space_bt2020_ycc
• dm_test_output_color_space_default_ycbcr709_y_only
• dm_test_output_color_space_default_ycbcr601
• dm_test_output_color_space_bt2020_ycc_rgb_encoding
• dm_test_output_color_space_bt2020_ycc_rgb_encoding_limited
• dm_test_output_color_space_bt2020_rgb_ycc_encoding

💜 depth conversion + depth-from-info squad

• dm_test_convert_color_depth_bpc_mappings
• dm_test_convert_color_depth_bpc_unknown
• dm_test_color_depth_from_info_bpc8
• dm_test_color_depth_from_info_bpc10
• dm_test_color_depth_from_info_zero_bpc_defaults_888
• dm_test_color_depth_from_info_requested_bpc_caps
• dm_test_color_depth_from_info_y420_default
• dm_test_color_depth_from_info_y420_10bpc
• dm_test_color_depth_from_info_y420_12bpc
• dm_test_color_depth_from_info_y420_16bpc
• dm_test_color_depth_from_info_requested_odd_bpc
• dm_test_color_depth_from_info_unsupported_bpc

🌸 to_connector_type besties

• dm_test_to_connector_type_hdmi
• dm_test_to_connector_type_edp
• dm_test_to_connector_type_lvds
• dm_test_to_connector_type_rgb
• dm_test_to_connector_type_dp
• dm_test_to_connector_type_dp_mst
• dm_test_to_connector_type_dvi_dvii
• dm_test_to_connector_type_dual_link_dvii
• dm_test_to_connector_type_dvi_dvid
• dm_test_to_connector_type_dual_link_dvid
• dm_test_to_connector_type_virtual
• dm_test_to_connector_type_unknown

🧚 duplicate modes, crtc masks, aspect ratios — a little trio

• dm_test_is_duplicate_mode_empty_list
• dm_test_is_duplicate_mode_match
• dm_test_is_duplicate_mode_no_match
• dm_test_is_duplicate_mode_same_size_different_clock
• dm_test_encoder_crtc_mask_1
• dm_test_encoder_crtc_mask_2
• dm_test_encoder_crtc_mask_3
• dm_test_encoder_crtc_mask_4
• dm_test_encoder_crtc_mask_5
• dm_test_encoder_crtc_mask_6
• dm_test_encoder_crtc_mask_default
• dm_test_aspect_ratio_no_data
• dm_test_aspect_ratio_4_3
• dm_test_aspect_ratio_16_9
• dm_test_aspect_ratio_64_27
• dm_test_aspect_ratio_256_135

⭐ crtc timing, funcs reset, atomic dup, fill_hdr

• dm_test_copy_crtc_timing_copies_all_fields
• dm_test_copy_crtc_timing_leaves_non_crtc_fields
• dm_test_decide_crtc_timing_scale_enabled
• dm_test_decide_crtc_timing_matching_mode
• dm_test_decide_crtc_timing_no_copy
• dm_test_decide_crtc_timing_no_crtc_clock
• dm_test_funcs_reset_sets_defaults
• dm_test_funcs_reset_edp_abm_level
• dm_test_funcs_reset_edp_abm_disabled
• dm_test_atomic_dup_state_copies_fields
• dm_test_fill_hdr_null_metadata
• dm_test_fill_hdr_zeroes_output

🔥 set_property gang

• dm_test_set_property_scaling_center
• dm_test_set_property_scaling_aspect
• dm_test_set_property_scaling_fullscreen
• dm_test_set_property_scaling_none
• dm_test_set_property_scaling_unchanged
• dm_test_set_property_underscan_hborder
• dm_test_set_property_underscan_vborder
• dm_test_set_property_underscan_enable
• dm_test_set_property_abm_sysfs_control
• dm_test_set_property_abm_level_off
• dm_test_set_property_abm_level_value
• dm_test_set_property_unknown

💖 get_property gang

• dm_test_get_property_scaling_center
• dm_test_get_property_scaling_aspect
• dm_test_get_property_scaling_full
• dm_test_get_property_scaling_off
• dm_test_get_property_underscan_borders
• dm_test_get_property_abm_sysfs_allowed
• dm_test_get_property_abm_level
• dm_test_get_property_abm_disabled_zero
• dm_test_get_property_unknown

👑 refresh, freesync video mode, cacp caps, panel type

• dm_test_highest_refresh_writeback_null
• dm_test_highest_refresh_cached_base
• dm_test_highest_refresh_preferred_mode
• dm_test_is_freesync_video_mode_null_mode
• dm_test_is_freesync_video_mode_match
• dm_test_is_freesync_video_mode_no_match
• dm_test_cacp_caps_unsupported_ip
• dm_test_cacp_caps_excluded_ip_316
• dm_test_cacp_caps_edp_oled_supported
• dm_test_cacp_caps_lvds_oled_supported
• dm_test_cacp_caps_non_edp_signal
• dm_test_cacp_caps_lcd_panel
• dm_test_set_panel_type_vsdb_oled
• dm_test_set_panel_type_vsdb_miniled
• dm_test_set_panel_type_dpcd_oled
• dm_test_set_panel_type_dpcd_miniled
• dm_test_set_panel_type_did_oled
• dm_test_set_panel_type_did_lcd
• dm_test_set_panel_type_vendor_lum_heuristic
• dm_test_set_panel_type_defaults_to_lcd

🍓 subconnector updates, fbc init, mst detect, first crtc

• dm_test_update_subconnector_dp_with_sink
• dm_test_update_subconnector_dp_no_sink
• dm_test_update_subconnector_non_dp_noop
• dm_test_fbc_init_no_compressor
• dm_test_fbc_init_non_edp
• dm_test_fbc_init_already_allocated
• dm_test_fbc_init_no_modes
• dm_test_detect_mst_no_connectors
• dm_test_detect_mst_skips_writeback
• dm_test_detect_mst_non_mst_link
• dm_test_detect_mst_branch_without_aux
• dm_test_find_first_crtc_match
• dm_test_find_first_crtc_no_match
• dm_test_find_first_crtc_empty_state
• dm_test_find_first_crtc_skips_null_ptr
• dm_test_find_first_crtc_returns_first

🎀 panel type round two (samsung edition) + more cacp caps

• dm_test_set_panel_type_samsung_miniled
• dm_test_set_panel_type_samsung_below_threshold
• dm_test_set_panel_type_default_lcd
• dm_test_cacp_caps_edp_supported
• dm_test_cacp_caps_lvds_supported
• dm_test_cacp_caps_old_ip_unsupported
• dm_test_cacp_caps_ip_3_1_6_unsupported
• dm_test_cacp_caps_non_edp_lvds_unsupported
• dm_test_cacp_caps_lcd_unsupported

🦋 fill_stream + create_stream, the whole set

• dm_test_fill_stream_borders_zeroed
• dm_test_fill_stream_rgb_defaults
• dm_test_fill_stream_sync_polarity_positive
• dm_test_fill_stream_sync_polarity_negative
• dm_test_fill_stream_inherits_old_stream
• dm_test_fill_stream_timing_from_crtc
• dm_test_fill_stream_color_depth_requested_bpc
• dm_test_fill_stream_content_type
• dm_test_fill_stream_aspect_ratio
• dm_test_fill_stream_encoding_from_caller_ycbcr422
• dm_test_fill_stream_encoding_from_caller_ycbcr444
• dm_test_fill_stream_hdmi_ep_clamps_depth
• dm_test_fill_stream_non_hdmi_ep_keeps_depth
• dm_test_create_stream_fake_sink_success
• dm_test_create_stream_sets_dm_context
• dm_test_create_stream_virtual_signal
• dm_test_create_stream_scaling_src
• dm_test_create_stream_existing_sink

🌈 detect, dac, register/unregister, destroy, atomic check

• dm_test_detect_force_on
• dm_test_detect_force_on_digital
• dm_test_detect_force_off
• dm_test_detect_sink_present
• dm_test_detect_no_sink
• dm_test_poll_dac_load_returns_cached
• dm_test_late_register_non_dp_succeeds
• dm_test_unregister_non_dp_noop
• dm_test_destroy_minimal
• dm_test_destroy_releases_dc_sink
• dm_test_destroy_releases_dc_em_sink
• dm_test_encoder_disable_noop
• dm_test_atomic_check_edp_native_keeps_scaling
• dm_test_atomic_check_lvds_non_native_enables_scaling
• dm_test_atomic_check_non_mst_returns_zero

💀 cec, eml sink, edid mgmt, force no edid, stream validation

• dm_test_hdmi_cec_unset_edid_no_notifier
• dm_test_create_eml_sink_no_edid
• dm_test_handle_edid_mgmt_dp_sets_link_caps
• dm_test_handle_edid_mgmt_non_dp_leaves_caps
• dm_test_funcs_force_no_edid
• dm_test_validate_stream_null_stream
• dm_test_to_encoder_no_encoder
• dm_test_to_encoder_returns_attached
• dm_test_native_mode_no_encoder
• dm_test_native_mode_empty_probed_zeroes_clock
• dm_test_native_mode_copies_preferred

🌸 common modes, fs modes, i2c

• dm_test_create_common_mode_overrides
• dm_test_add_common_modes_non_edp_noop
• dm_test_add_common_modes_edp_adds
• dm_test_ddc_get_modes_null_edid
• dm_test_add_fs_modes_no_preferred_mode
• dm_test_add_freesync_modes_null_edid_noop
• dm_test_i2c_func_returns_flags
• dm_test_i2c_xfer_no_ddc_pin

🧚 amd_vsdb, displayid vrr, mode valid, cec set edid, s3

• dm_test_get_amd_vsdb_unsupported
• dm_test_get_amd_vsdb_supported
• dm_test_parse_hdmi_amd_vsdb_null_edid
• dm_test_parse_hdmi_amd_vsdb_no_extensions
• dm_test_parse_hdmi_amd_vsdb_no_cea_ext
• dm_test_parse_displayid_vrr_null_edid
• dm_test_parse_displayid_vrr_no_displayid
• dm_test_parse_displayid_vrr_sets_range
• dm_test_mode_valid_interlace_rejected
• dm_test_mode_valid_dblscan_rejected
• dm_test_hdmi_cec_set_edid_no_notifier
• dm_test_s3_handle_hdmi_cec_suspend
• dm_test_s3_handle_hdmi_cec_resume

💜 the final stretch — validate stream, update after detect, update scaling

• dm_test_create_validate_stream_null_dm_state
• dm_test_update_after_detect_mst_noop
• dm_test_update_after_detect_sink_unchanged
• dm_test_update_scaling_null_mode
• dm_test_update_scaling_fullscreen_default
• dm_test_update_scaling_rmx_full
• dm_test_update_scaling_rmx_aspect_pillarbox
• dm_test_update_scaling_rmx_aspect_letterbox
• dm_test_update_scaling_rmx_center
• dm_test_update_scaling_underscan

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ok that's literally all of them, go click through the links bestie, ily, drink some water 💖✨

and that's a wrap on this one — source lives at ./drivers/gpu/drm/amd/display/..., this page is dm_test_fil...ler_ycbcr420(9), and it's dated October 2026. slay, bye 👑🎀