usb4_port_re...m_set_offset(9)

💅 NAME 💅

usb4_port_retimer_nvm_set_offset — set the NVM write offset, bestie 💖

so this page is straight out of the Kernel API Manual, section 9, and it's about one very specific lil job: telling a retimer's NVM exactly where to start writing. iconic behavior only ✨

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🎀 SYNOPSIS 🎀

int usb4_port_retimer_nvm_set_offset (struct tb_port *port , u8 index ,
unsigned int address );

like, that's the whole call. three args, one int back. no cap 🫶

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🌸 ARGUMENTS 🌸

• port — the USB4 port in question, your main character 🦋
• index — which retimer we're talking about (the Retimer index)
• address — where the writing starts, aka the Start offset ✨

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🧚 DESCRIPTION 🧚

okay so here's the tea ☕ — this function explicitly sets the NVM write offset. like, you're hand-picking the spot. deliberately. on purpose. 💅

now normally? when you're writing to NVM, this whole thing is done automatically by usb4_port_retimer_nvm_write. so this function is the "i'll do it myself" option, iykyk 😭

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⭐ RETURN ⭐

• 0 on success 🎉
• a negative errno otherwise 💀

that's it, that's the vibe check.

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🌈 SEE ALSO 🌈

the kernel file lives at ./drivers/thunderbolt/usb4.c 📁 and honestly the whole friend group shows up here, so let's go:

• 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_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_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)

like... the whole extended universe showed up to the group chat 😭 adorable.

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ngl this one's short but it matters — if you're hand-rolling NVM writes, you're the one responsible for the offset, and nobody's gonna do it for you 💀

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that's the page, bestie!! 🫶 written from ./drivers/thunderbolt, dated October 2026, and honestly? she ate. periodt 💅✨🎀