igc_force_mac_fc(9)

💅 igc_force_mac_fc 💅

okay so welcome to the igc_force_mac_fc(9) page from the Kernel API Manual, bestie — yes, the actual Kernel API Manual, and this function is lowkey doing MAC flow-control glamour work. ✨

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🌸 NAME 🌸

igc_force_mac_fc — force the MAC's flow control settings, periodt 💅

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🦋 SYNOPSIS 🦋

s32 igc_force_mac_fc (struct igc_hw *hw );

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🎀 ARGUMENTS 🎀

• hw — pointer to the HW structure, aka your little handle to the hardware situation 🫶

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✨ DESCRIPTION ✨

So this one literally forces the MAC's flow control settings. It sets the TFCE and RFCE bits in the device control register so they reflect the adapter settings — yes, those exact bits, no cap.

TFCE and RFCE need to be explicitly set by software when a copper PHY is used, because autonegotiation is managed by the PHY rather than the MAC. Software must also configure these bits when link is forced on a fiber connection. That's the whole vibe check: software has to do the setting in those cases. 💖

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🌈 SEE ALSO 🌈

Kernel file:

./drivers/net/ethernet/intel/igc/igc_mac.c

also go peek at these besties:

• igc_disable_pcie_master(9)
• igc_init_rx_addrs(9)
• igc_set_fc_watermarks(9)
• igc_setup_link(9)
• igc_clear_hw_cntrs_base(9)
• igc_rar_set(9)
• igc_check_for_copper_link(9)
• igc_config_collision_dist(9)
• igc_config_fc_after_link_up(9)
• igc_get_auto_rd_done(9)
• igc_get_speed_and_duplex_copper(9)
• igc_put_hw_semaphore(9)
• igc_enable_mng_pass_thru(9)
• igc_hash_mc_addr(9)
• igc_update_mc_addr_list(9)

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cute sign-off time: this page lives under ./drivers/net/ethernet/intel/igc, dated October 2026, and it's igc_force_mac_fc(9) — bye bestie, slay your flow control 💖✨