usb4_dp_port_nrd(9)

💖 usb4_dp_port_nrd(9) — Kernel API Manual 💖

okay bestie, welcome to the usb4_dp_port_nrd(9) page from the Kernel API Manual ✨ this one is short and sweet, and it's basically the “read the non-reduced rate and lanes” bestie of the USB4 crew 💅

🌸 NAME 🌸

usb4_dp_port_nrd — Read non-reduced rate and lanes 🎀

✨ SYNOPSIS ✨

int usb4_dp_port_nrd (struct tb_port *port , int *rate , int *lanes );

like, that's the whole call signature, no cap 🫶

🎀 ARGUMENTS 🎀

• port — DP IN adapter 💖
• rate — Non-reduced rate in Mb/s is placed here 🌈
• lanes — Non-reduced lanes are placed here 🦋

💅 DESCRIPTION 💅

Reads the non-reduced rate and lanes from the DP IN adapter. That's literally the whole description, bestie — it's giving short king energy 👑✨

🫶 RETURN 🫶

It hands back one of these:

• 0 - On success 🎉
• -EOPNOTSUPP - If the adapter does not support this 😭
• Negative errno - Another error occurred 💀

🔥 SEE ALSO 🔥

Kernel file ./drivers/thunderbolt/usb4.c is right here, and these are the linked besties, fr fr:

• usb4_switch_check_wakes(9)
• usb4_switch_setup(9)
• usb4_switch_configuration_valid(9)
• usb4_switch_read_uid(9)
• usb4_switch_drom_read(9)
• usb4_switch_lane_bonding_possible(9)
• usb4_switch_set_wake(9)
• usb4_switch_set_sleep(9)
• usb4_switch_nvm_sector_size(9)
• usb4_switch_nvm_read(9)
• usb4_switch_nvm_set_offset(9)
• usb4_switch_nvm_write(9)
• usb4_switch_nvm_authenticate(9)
• usb4_switch_nvm_authenticate_status(9)
• usb4_switch_credits_init(9)
• usb4_switch_query_dp_resource(9)
• usb4_switch_alloc_dp_resource(9)
• usb4_switch_dealloc_dp_resource(9)
• usb4_port_index(9)
• usb4_switch_map_pcie_down(9)
• usb4_switch_map_usb3_down(9)
• usb4_switch_add_ports(9)
• usb4_switch_remove_ports(9)
• usb4_port_unlock(9)
• usb4_port_hotplug_enable(9)
• usb4_port_reset(9)
• usb4_port_configure(9)
• usb4_port_unconfigure(9)
• usb4_port_configure_xdomain(9)
• usb4_port_unconfigure_xdomain(9)
• usb4_port_sb_read(9)
• usb4_port_sb_write(9)
• usb4_port_router_offline(9)
• usb4_port_router_online(9)
• usb4_port_enumerate_retimers(9)
• usb4_port_clx_supported(9)
• usb4_port_asym_supported(9)
• usb4_port_asym_set_link_width(9)
• usb4_port_asym_start(9)
• usb4_port_margining_caps(9)
• usb4_port_hw_margin(9)
• usb4_port_sw_margin(9)
• usb4_port_sw_margin_errors(9)
• usb4_port_retimer_set_inbound_sbtx(9)
• usb4_port_retimer_unset_inbound_sbtx(9)
• usb4_port_retimer_is_last(9)
• usb4_port_retimer_is_cable(9)
• usb4_port_retimer_nvm_sector_size(9)
• usb4_port_retimer_nvm_set_offset(9)
• usb4_port_retimer_nvm_write(9)
• usb4_port_retimer_nvm_authenticate(9)
• usb4_port_retimer_nvm_authenticate_status(9)
• usb4_port_retimer_nvm_read(9)
• usb4_usb3_port_max_link_rate(9)
• usb4_usb3_port_allocated_bandwidth(9)
• usb4_usb3_port_allocate_bandwidth(9)
• usb4_usb3_port_release_bandwidth(9)
• usb4_dp_port_set_cm_id(9)
• usb4_dp_port_bandwidth_mode_supported(9)
• usb4_dp_port_bandwidth_mode_enabled(9)
• usb4_dp_port_set_cm_bandwidth_mode_supported(9)
• usb4_dp_port_group_id(9)
• usb4_dp_port_set_group_id(9)
• usb4_dp_port_set_nrd(9)
• usb4_dp_port_granularity(9)
• usb4_dp_port_set_granularity(9)
• usb4_dp_port_set_estimated_bandwidth(9)
• usb4_dp_port_allocated_bandwidth(9)
• usb4_dp_port_allocate_bandwidth(9)
• usb4_dp_port_requested_bandwidth(9)
• usb4_pci_port_set_ext_encapsulation(9)
• usb4_pci_port_ltssm_state(9)

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okay that's the whole page, bestie 💖 source/version: ./drivers/thunderbolt · date: October 2026 — mwah 💋✨