STRUCT USB4_PORT_MARGINING_PARAMS(9)

🌸 struct usb4_port_margining_params(9) 🌸

okay so this is from the Kernel API Manual bestie, and we're about to get deep into USB4 margining parameters 💅 like this is the struct that holds all the little knobs for margin testing, and ngl she's lowkey iconic for it 🎀

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✨ NAME ✨

struct usb4_port_margining_params — USB4 margining parameters, that's the whole vibe 🦋

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🌈 SYNOPSIS 🌈

struct usb4_port_margining_params {
    enum usb4_margin_sw_error_counter error_counter;
    u32 ber_level;
    enum usb4_margining_lane lanes;
    u32 voltage_time_offset;
    bool optional_voltage_offset_range;
    bool right_high;
    bool upper_eye;
    bool time;
 };

like, that's her. that's the whole struct. no cap 💖

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👑 Members 👑

okay so every single field gets her moment, periodt:

• error_counter — the error counter operation for software margining 💫 like that's what she's here for
• ber_level — the current BER level contour value ⭐ (BER = bit error rate, and she's got a contour value)
• lanes — the lanes to enable for the margining operation 🦋 which ones are we turning on, bestie
• voltage_time_offset — the offset for voltage / time for software margining 🎀 that's the whole point of her
• optional_voltage_offset_range — enable the optional extended voltage range 🔥 she's got range, literally
• right_high — false if a left/low margin test is performed, true if right/high 🌸 so like, pick a side
• upper_eye — true if the margin test is done on the upper eye, false if done on the lower eye 👁️✨ eye diagram moment
• time — true if time margining is used instead of voltage ⏰ she can do either, she's flexible like that

fr fr though — right_high, upper_eye, and time are all booleans where the meaning flips depending on the value, so don't just assume true = "good". read the description, bestie 🙈

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🫶 SEE ALSO 🫶

okay this list is long but we do not skip a single one, iykyk 😭 she's connected to the whole thunderbolt family:

Kernel file ./drivers/thunderbolt/tb.h — and also: 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_path(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)

like… she knows everyone 💀💖

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🧚 sign-off 🧚

this little page lives in ./drivers/thunderbolt, and the version stamp is October 2026 📅 so yeah, she's from the future, slay ⭐ and the title up top is struct usb4...ining_params(9) in case you forgot where you were 💜

go forth and margin, bestie — ate and left no crumbs 🍓✨