STRUCT TB_PATH(9)

struct tb_path(9) 🦋

Okay so this is the Kernel API Manual page for struct tb_path(9) — welcome to the group chat, bestie 💅

💖 NAME 💖

struct tb_path — a unidirectional path between two ports. That's the whole vibe: one-way path, two ports, iconic.

✨ SYNOPSIS ✨

struct tb_path {
    struct tb *tb;
    const char *name;
    enum tb_path_port ingress_shared_buffer;
    enum tb_path_port egress_shared_buffer;
    enum tb_path_port ingress_fc_enable;
    enum tb_path_port egress_fc_enable;
    unsigned int priority:3;
    int weight:4;
    bool drop_packages;
    bool activated;
    bool clear_fc;
    int path_length;
    bool alloc_hopid;
    struct tb_path_hop hops[];
};

🫶 Members 🫶

Meet the fields, bestie — every single one is here, no skipping:

• tb — pointer to the domain structure 🫶
• name — name of the path, used for debugging 👀
• ingress_shared_buffer — shared buffering used for ingress ports on the path ✨
• egress_shared_buffer — shared buffering used for egress ports on the path ✨
• ingress_fc_enable — flow control for ingress ports on the path 💫
• egress_fc_enable — flow control for egress ports on the path 💫
• priority — priority group if the path — the page says if, and we're keeping it, periodt 💅
• weight — weight of the path inside the priority group — very main character energy 👑
• drop_packages — drop packages from queue tail or head — yes, packages is the word on the page, no cap 🤭
• activated — is the path active? a yes/no vibe 💖
• clear_fc — clear all flow control from the path config space entries when deactivating this path 🧚
• path_length — how many hops the path uses 🎀
• alloc_hopid — does this path consume port HopID? 🦋
• hops — path hops 🌸

🌸 Description 🌸

A path consists of a number of hops (see struct tb_path_hop), bestie. To establish a PCIe tunnel, two paths have to be created between the two PCIe ports — that's the rule, periodt 🔥

🔥 SEE ALSO 🔥

Go read these, iykyk — starting with the kernel file:

• Kernel file ./drivers/thunderbolt/tb.h
• struct tb_nvm(9)
• enum tb_switch_tmu_mode(9)
• struct tb_switch_tmu(9)
• struct tb_switch(9)
• struct tb_bandwidth_group(9)
• struct tb_port(9)
• struct usb4_port(9)
• struct tb_retimer(9)
• struct tb_path_hop(9)
• enum tb_path_port(9)
• struct tb_cm_ops(9)
• tb_upstream_port(9)
• tb_is_upstream_port(9)
• tb_port_has_remote(9)
• tb_domain_event(9)
• tb_switch_for_each_port(9)
• tb_switch_downstream_port(9)
• tb_switch_depth(9)
• tb_switch_is_icm(9)
• tb_switch_tmu_is_configured(9)
• tb_switch_tmu_is_enabled(9)
• tb_switch_clx_is_enabled(9)
• tb_port_path_direction_downstream(9)
• tb_for_each_port_on_path(9)
• tb_for_each_upstream_port_on_path(9)
• tb_path_for_each_hop(9)
• tb_downstream_route(9)
• tb_xdomain_downstream_port(9)
• usb4_switch_version(9)
• tb_switch_is_usb4(9)
• enum usb4_sb_target(9)
• enum usb4_margin_sw_error_counter(9)
• struct usb4_port_margining_params(9)

Sign-off bestie: source/version ./drivers/thunderbolt, date October 2026, title struct tb_path(9) — mwah! 💋✨