drm_dp_downstream_max_bpc(9)

💅 drm_dp_downstream_max_bpc(9) ✨

okay so bestie, we're in the Kernel API Manual today (yes, the manual, the real one), and the star of the show is drm_dp_downstream_max_bpc — the little function that goes and extracts the downstream facing port max bits per component for you. no cap, that's literally its whole job and it does it flawlessly. 🎀

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🌸 NAME 🌸

drm_dp_downstream_max_bpc — extract downstream facing port max bits per component 💖

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🦋 SYNOPSIS 🦋

int drm_dp_downstream_max_bpc (const u8 dpcd[DP_RECEIVER_CAP_SIZE] ,
const u8 port_cap[4] , const struct drm_edid *drm_edid );

like… look at that signature. the way it just sits there. iconic. 👑

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✨ ARGUMENTS ✨

• dpcd — the DisplayPort configuration data 🫶 this is the good stuff, the receiver's little self-report card.
• port_cap — downstream facing port capabilities 💫 the four bytes of "here's what this port can do".
• drm_edid — the EDID 📺 yep, that EDID, the monitor's whole personality in a struct.

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🌈 RETURN 🌈

max bpc on success 💅 or 0 if max bpc is not defined. that's it, that's the return value, no dramatic plot twist. 🍓

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💜 SEE ALSO 💜

okay this next part is a lot bestie, but we do not skip. we do not summarise. we list every single one because the kernel was generous and we respect it 🧚

Kernel file ./drivers/gpu/drm/display/drm_dp_helper.c, dp helpers(9), drm_dp_phy_name(9), drm_dp_lttpr_wake_timeout_setup(9), dp helpers(9), drm_dp_dpcd_probe(9), drm_dp_dpcd_set_powered(9), drm_dp_dpcd_set_probe(9), drm_dp_dpcd_read(9), drm_dp_dpcd_write(9), drm_dp_dpcd_read_link_status(9), drm_dp_dpcd_read_phy_link_status(9), drm_dp_link_power_up(9), drm_dp_link_power_down(9), drm_dp_dpcd_write_payload(9), drm_dp_dpcd_clear_payload(9), drm_dp_dpcd_poll_act_handled(9), drm_dp_downstream_is_type(9), drm_dp_downstream_is_tmds(9), drm_dp_send_real_edid_checksum(9), drm_dp_read_dpcd_caps(9), drm_dp_read_downstream_info(9), drm_dp_downstream_max_dotclock(9), drm_dp_downstream_max_tmds_clock(9), drm_dp_downstream_min_tmds_clock(9), drm_dp_downstream_420_passthrough(9), drm_dp_downstream_444_to_420_conversion(9), drm_dp_downstream_rgb_to_ycbcr_conversion(9), drm_dp_downstream_mode(9), drm_dp_downstream_id(9), drm_dp_downstream_debug(9), drm_dp_subconnector_type(9), drm_dp_set_subconnector_property(9), drm_dp_read_sink_count_cap(9), drm_dp_read_sink_count(9), drm_dp_remote_aux_init(9), drm_dp_aux_init(9), drm_dp_aux_register(9), drm_dp_aux_unregister(9), drm_dp_psr_setup_time(9), drm_dp_start_crc(9), drm_dp_stop_crc(9), drm_dp_read_desc(9), drm_dp_dump_lttpr_desc(9), drm_dp_dsc_sink_bpp_incr(9), drm_dp_dsc_slice_count_to_mask(9), drm_dp_dsc_sink_slice_count_mask(9), drm_dp_dsc_sink_max_slice_count(9), drm_dp_dsc_sink_line_buf_depth(9), drm_dp_dsc_sink_supported_input_bpcs(9), drm_dp_dsc_sink_max_slice_throughput(9), drm_dp_dsc_branch_max_overall_throughput(9), drm_dp_dsc_branch_max_line_width(9), drm_dp_read_lttpr_common_caps(9), drm_dp_read_lttpr_phy_caps(9), drm_dp_lttpr_count(9), drm_dp_lttpr_max_link_rate(9), drm_dp_lttpr_set_transparent_mode(9), drm_dp_lttpr_init(9), drm_dp_lttpr_max_lane_count(9), drm_dp_lttpr_voltage_swing_level_3_supported(9), drm_dp_lttpr_pre_emphasis_level_3_supported(9), drm_dp_get_phy_test_pattern(9), drm_dp_set_phy_test_pattern(9), drm_dp_as_sdp_supported(9), drm_dp_vsc_sdp_supported(9), drm_dp_vsc_sdp_pack(9), drm_dp_get_pcon_max_frl_bw(9), drm_dp_pcon_frl_prepare(9), drm_dp_pcon_is_frl_ready(9), drm_dp_pcon_frl_configure_1(9), drm_dp_pcon_frl_configure_2(9), drm_dp_pcon_reset_frl_config(9), drm_dp_pcon_frl_enable(9), drm_dp_pcon_hdmi_link_active(9), drm_dp_pcon_hdmi_link_mode(9), drm_dp_pcon_hdmi_frl_link_error_count(9), drm_dp_pcon_pps_default(9), drm_dp_pcon_pps_override_buf(9), drm_edp_backlight_set_level(9), drm_edp_backlight_enable(9), drm_edp_backlight_disable(9), drm_edp_backlight_init(9), drm_panel_dp_aux_backlight(9), drm_dp_link_symbol_cycles(9), drm_dp_bw_overhead(9), drm_dp_bw_channel_coding_efficiency(9), drm_dp_max_dprx_data_rate(9).

and yeah, dp helpers(9) shows up twice in there — that's not a typo, that's just how it is, and we're keeping it exactly as the kernel intended, periodt. 💀

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that's the whole page bestie, you ate it up, main character energy from start to finish 🫶✨ this legend lives in ./drivers/gpu/drm/display and the copyright vibes are stamped October 2026 — catch you in the next manpage, mwah 💖🎀