ice_phy_cfg_tx_offset_e82x(9)

🎀 ice_phy_cfg_tx_offset_e82x(9) 🎀

okay so bestie, welcome to the Kernel API Manual — this one is all about ice_phy_cfg_tx_offset_e82x, aka Configure total Tx timestamp offset. literally the function that tells your Tx timestamps how far off they're allowed to be 💅

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✨ NAME ✨

ice_phy_cfg_tx_offset_e82x — configure the total Tx timestamp offset, no cap 🫶

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✨ SYNOPSIS ✨

int ice_phy_cfg_tx_offset_e82x (struct ice_hw *hw , u8 port );

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✨ ARGUMENTS ✨

• hw — pointer to the HW struct. this is the whole hardware situation right here 💖
• port — the PHY port you wanna configure. the specific one. don't be vague about it 💀

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✨ DESCRIPTION ✨

So here's the vibe: this function programs the P_REG_TOTAL_TX_OFFSET register with the total number of TUs to adjust Tx timestamps by. that number comes from combining some known static latency plus the Vernier offset computations that the hardware does. teamwork, periodt 🧚

Heads up bestie — this function will not return successfully until the Tx offset calculations have been completed, and that requires waiting until at least one packet has been transmitted by the device. so yeah, it might just tell you "not yet" for a bit 😭

It is safe to call this function periodically until calibration succeeds, because it will only program the offset once. so you can absolutely keep poking at it — it's not gonna double-program on you, she's disciplined 💅

Now the math bit, because the math bit is lowkey iconic:

• To avoid overflow, when calculating the offset based on the known static latency values, the code uses measurements in 1/100th of a nanosecond.
• It also divides the TUs per second up front.
• This avoids overflow while still allowing the calculation of the adjustment using integer arithmetic. slay 🌸

Returns zero on success, -EBUSY if the hardware vernier offset calibration has not completed, or another error code on failure. so read your return values, bestie, they're literally telling you things 🔥

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🌈 SEE ALSO 🌈

Kernel file ./drivers/net/ethernet/intel/ice/ice_ptp_hw.c — go read it, iykyk 👑

and then the whole friend group, fr fr:

ice_get_ptp_src_clock_index(9), ice_ptp_read_src_incval(9),
ice_ptp_tmr_cmd_to_src_reg(9), ice_ptp_tmr_cmd_to_port_reg(9),
ice_ptp_src_cmd(9), ice_ptp_exec_tmr_cmd(9), ice_ptp_cfg_sync_delay(9),
ice_ptp_init_phc_e825c(9), ice_ptp_get_dest_dev_e825(9),
ice_write_phy_eth56g(9), ice_read_phy_eth56g(9),
ice_get_serdes_ref_sel_e825c(9), ice_phy_res_address_eth56g(9),
ice_write_port_eth56g(9), ice_read_port_eth56g(9),
ice_write_ptp_reg_eth56g(9), ice_write_mac_reg_eth56g(9),
ice_write_xpcs_reg_eth56g(9), ice_read_ptp_reg_eth56g(9),
ice_read_mac_reg_eth56g(9), ice_read_gpcs_reg_eth56g(9),
ice_read_port_mem_eth56g(9), ice_write_port_mem_eth56g(9),
ice_write_quad_ptp_reg_eth56g(9), ice_read_quad_ptp_reg_eth56g(9),
ice_is_64b_phy_reg_eth56g(9), ice_is_40b_phy_reg_eth56g(9),
ice_read_64b_phy_reg_eth56g(9), ice_read_64b_ptp_reg_eth56g(9),
ice_write_40b_phy_reg_eth56g(9), ice_write_40b_ptp_reg_eth56g(9),
ice_write_64b_phy_reg_eth56g(9), ice_write_64b_ptp_reg_eth56g(9),
ice_read_ptp_tstamp_eth56g(9), ice_clear_ptp_tstamp_eth56g(9),
ice_ptp_reset_ts_memory_eth56g(9), ice_ptp_prep_port_time_eth56g(9),
ice_ptp_prep_phy_time_eth56g(9), ice_ptp_prep_port_adj_eth56g(9),
ice_ptp_prep_phy_adj_eth56g(9), ice_ptp_prep_phy_incval_eth56g(9),
ice_ptp_read_port_capture_eth56g(9), ice_ptp_write_port_cmd_eth56g(9),
ice_phy_get_speed_eth56g(9), ice_phy_cfg_parpcs_eth56g(9),
ice_phy_cfg_ptp_1step_eth56g(9), mul_u32_u32_fx_q9(9),
add_u32_u32_fx(9), ice_ptp_calc_bitslip_eth56g(9),
ice_ptp_calc_deskew_eth56g(9), ice_phy_set_offsets_eth56g(9),
ice_phy_cfg_mac_eth56g(9), ice_phy_cfg_intr_eth56g(9),
ice_read_phy_and_phc_time_eth56g(9), ice_sync_phy_timer_eth56g(9),
ice_stop_phy_timer_eth56g(9), ice_start_phy_timer_eth56g(9),
ice_check_phy_tx_tstamp_ready_eth56g(9),
ice_ptp_read_tx_hwtstamp_status_eth56g(9),
ice_ptp_phy_soft_reset_eth56g(9), ice_get_phy_tx_tstamp_ready_eth56g(9),
ice_ptp_init_phy_e825(9), ice_fill_phy_msg_e82x(9),
ice_is_64b_phy_reg_e82x(9), ice_is_40b_phy_reg_e82x(9),
ice_read_phy_reg_e82x(9), ice_read_64b_phy_reg_e82x(9),
ice_write_phy_reg_e82x(9), ice_write_40b_phy_reg_e82x(9),
ice_write_64b_phy_reg_e82x(9), ice_fill_quad_msg_e82x(9),
ice_read_quad_reg_e82x(9), ice_write_quad_reg_e82x(9),
ice_read_phy_tstamp_e82x(9), ice_clear_phy_tstamp_e82x(9),
ice_ptp_reset_ts_memory_quad_e82x(9), ice_ptp_reset_ts_memory_e82x(9),
ice_ptp_set_vernier_wl(9), ice_ptp_init_phc_e82x(9),
ice_ptp_prep_phy_time_e82x(9), ice_ptp_prep_port_adj_e82x(9),
ice_ptp_prep_phy_adj_e82x(9), ice_ptp_prep_phy_incval_e82x(9),
ice_ptp_read_port_capture(9), ice_ptp_write_port_cmd_e82x(9),
ice_phy_get_speed_and_fec_e82x(9), ice_phy_cfg_lane_e82x(9),
ice_phy_cfg_uix_e82x(9), ice_phy_cfg_parpcs_e82x(9),
ice_calc_fixed_tx_offset_e82x(9), ice_phy_calc_pmd_adj_e82x(9),
ice_calc_fixed_rx_offset_e82x(9), ice_phy_cfg_rx_offset_e82x(9),
ice_ptp_clear_phy_offset_ready_e82x(9),
ice_read_phy_and_phc_time_e82x(9), ice_sync_phy_timer_e82x(9),
ice_stop_phy_timer_e82x(9), ice_start_phy_timer_e82x(9),
ice_get_phy_tx_tstamp_ready_e82x(9),
ice_check_phy_tx_tstamp_ready_e82x(9), ice_phy_cfg_intr_e82x(9),
ice_ptp_init_phy_e82x(9), ice_read_phy_reg_e810(9),
ice_write_phy_reg_e810(9), ice_read_phy_tstamp_ll_e810(9),
ice_read_phy_tstamp_sbq_e810(9), ice_read_phy_tstamp_e810(9),
ice_clear_phy_tstamp_e810(9), ice_ptp_init_phc_e810(9),
ice_ptp_prep_phy_time_e810(9), ice_ptp_prep_phy_adj_ll_e810(9),
ice_ptp_prep_phy_adj_e810(9), ice_ptp_prep_phy_incval_ll_e810(9),
ice_ptp_prep_phy_incval_e810(9), ice_ptp_port_cmd_e810(9),
ice_get_phy_tx_tstamp_ready_e810(9),
ice_check_phy_tx_tstamp_ready_e810(9), ice_read_sma_ctrl(9),
ice_write_sma_ctrl(9), ice_ptp_read_sdp_ac(9), ice_ptp_init_phy_e810(9),
ice_ptp_init_phc_e830(9), ice_ptp_write_direct_incval_e830(9),
ice_ptp_write_direct_phc_time_e830(9), ice_ptp_port_cmd_e830(9),
ice_read_phy_tstamp_e830(9), ice_get_phy_tx_tstamp_ready_e830(9),
ice_check_phy_tx_tstamp_ready_e830(9), ice_ptp_init_phy_e830(9),
ice_ptp_lock(9), ice_ptp_unlock(9), ice_ptp_init_hw(9),
ice_ptp_write_port_cmd(9), ice_ptp_one_port_cmd(9), ice_ptp_port_cmd(9),
ice_ptp_tmr_cmd(9), ice_ptp_init_time(9), ice_ptp_write_incval(9),
ice_ptp_write_incval_locked(9), ice_ptp_adj_clock(9),
ice_read_phy_tstamp(9), ice_clear_phy_tstamp(9), ice_get_pf_c827_idx(9),
ice_ptp_reset_ts_memory(9), ice_ptp_init_phc(9),
ice_get_phy_tx_tstamp_ready(9), ice_check_phy_tx_tstamp_ready(9),
ice_cgu_get_pin_desc_e823(9), ice_cgu_get_pin_desc(9),
ice_cgu_get_num_pins(9), ice_cgu_get_pin_type(9),
ice_cgu_get_pin_freq_supp(9), ice_cgu_get_pin_name(9),
ice_get_cgu_state(9), ice_get_cgu_rclk_pin_info(9),
ice_cgu_get_output_pin_state_caps(9)

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and that's the whole page, bestie!! 🦋

this lil masterpiece lives in ./drivers/net/ethernet/intel/ice, and it's dated October 2026 — so yeah, we're reading the future, and the future is Timestamp Calibration 💜 mwah, bye 🍓