igb_get_cable_length_igp_2(9)

💖 igb_get_cable_length_igp_2(9) 💖

okay bestie, welcome to this lil page from the Kernel API Manual — it's giving niche PHY lore and I'm obsessed. 🦋

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🌸 NAME 🌸

• igb_get_cable_length_igp_2 — Determine cable length for igp2 PHY

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✨ SYNOPSIS ✨

s32 igb_get_cable_length_igp_2 (struct e1000_hw *hw );

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🎀 ARGUMENTS 🎀

• hw — pointer to the HW structure 💖

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💅 DESCRIPTION 💅

okay so automatic gain control (agc) is literally the main character here: it normalizes the amplitude of the received signal and adjusts for the attenuation produced by the cable. no cap. ✨

By reading the AGC registers — which represent the combination of coarse and fine gain value — the value can be put into a lookup table to obtain the approximate cable length for each channel. that's the whole tea, fr fr. 🫶

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🔥 SEE ALSO 🔥

Kernel file: ./drivers/net/ethernet/intel/igb/e1000_phy.c

the whole linked-up squad, iykyk:

• igb_check_reset_block(9), igb_get_phy_id(9), igb_phy_reset_dsp(9), igb_read_phy_reg_mdic(9), igb_write_phy_reg_mdic(9), igb_read_phy_reg_i2c(9)
• igb_write_phy_reg_i2c(9), igb_read_sfp_data_byte(9), igb_read_phy_reg_igp(9), igb_write_phy_reg_igp(9), igb_copper_link_setup_82580(9), igb_copper_link_setup_m88(9)
• igb_copper_link_setup_m88_gen2(9), igb_copper_link_setup_igp(9), igb_copper_link_autoneg(9), igb_phy_setup_autoneg(9), igb_setup_copper_link(9), igb_phy_force_speed_duplex_igp(9)
• igb_phy_force_speed_duplex_m88(9), igb_phy_force_speed_duplex_setup(9), igb_set_d3_lplu_state(9), igb_check_downshift(9), igb_check_polarity_m88(9), igb_check_polarity_igp(9)
• igb_wait_autoneg(9), igb_phy_has_link(9), igb_get_cable_length_m88(9), igb_get_phy_info_m88(9), igb_get_phy_info_igp(9), igb_phy_sw_reset(9)
• igb_phy_hw_reset(9), igb_phy_init_script_igp3(9), igb_initialize_M88E1512_phy(9), igb_initialize_M88E1543_phy(9), igb_power_up_phy_copper(9), igb_power_down_phy_copper(9)
• igb_check_polarity_82580(9), igb_phy_force_speed_duplex_82580(9), igb_get_phy_info_82580(9), igb_get_cable_length_82580(9), igb_set_master_slave_mode(9)

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okay that's the page! source/version tea: ./drivers/net/ethernet/intel/igb; date tea: October 2026. mwah 💋