usb4_dp_port_granularity(9)

💅 NAME 💅

okay so we're in usb4_dp_port_granularity(9) territory, and the manual name is the Kernel API Manual — very demure, very mindful. This function? It returns the granularity for the bandwidth values. That's the whole assignment, bestie. 🎀

✨ SYNOPSIS ✨

int usb4_dp_port_granularity (struct tb_port *port );

🦋 ARGUMENTS 🦋

• port — the DP IN adapter. she's the main character here 💅

🌸 DESCRIPTION 🌸

It reads the programmed granularity from port. That's it. That's the vibe. No extra lore, no secret side quest — just reads the programmed granularity from the port. lowkey iconic for being so direct. ✨

💖 RETURN 💖

• Granularity value of a port. slay 💅
• -EOPNOTSUPP — if the DP IN adapter does not support bandwidth allocation mode. rude, but okay 😭
• Negative errno — another error occurred. not the vibe, but we move 🫶

bestie pls remember: -EOPNOTSUPP has a very specific meaning here — it's the "no bandwidth allocation mode for this DP IN adapter" situation, not just any random oopsie.

👑 SEE ALSO 👑

the whole extended friend group is literally right here — kernel file ./drivers/thunderbolt/usb4.c and the entire squad:

Kernel file ./drivers/thunderbolt/usb4.c 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_nrd(9), usb4_dp_port_set_nrd(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)

mwah 💋 this little love letter is from ./drivers/thunderbolt, dated October 2026 — and that's the whole page, bestie. go read the port granularity, slay, periodt. 🫶💖