phylink_pcs_neg_mode(9)

💅 phylink_pcs_neg_mode(9) — the Kernel API Manual, but make it make sense 🎀

okay so bestie, welcome to the Kernel API Manual corner of the universe ✨ this one's about the lil helper that figures out what negotiation mode your PCS should be in, and honestly? it's giving "small function, big responsibility" 👑

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✨ NAME ✨

phylink_pcs_neg_mode — the helper that decides your PCS's inband mode 💫 literally just a mode-picker, but make it networking.

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🦋 SYNOPSIS 🦋

void phylink_pcs_neg_mode (struct phylink *pl , struct phylink_pcs *pcs
, phy_interface_t interface , const unsigned long *advertising );

no cap, that's the whole signature 🫶

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🌸 ARGUMENTS 🌸

• pl — a pointer to a struct phylink that came back from phylink_create, the main character of this whole operation 💖
• pcs — a pointer to struct phylink_pcs, the actual piece of hardware we're negotiating on behalf of 🧚
• interface — the interface mode you wanna use, like, the vibe you're going for ✨
• advertising — the ethtool link mode mask you're advertising 🎀 (the og page spells it "adertisement" and honestly? iconic typo, we stan a legend with quirks 🫶 — anyway it's the advertisement mask, you get it)

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🔥 DESCRIPTION 🔥

So what does this lil function do? It determines the negotiation mode that the PCS is gonna use, and then returns one of these bad boys 👇

• PHYLINK_PCS_NEG_NONE — the interface mode straight up does not support inband, bestie. not today. 💀
• PHYLINK_PCS_NEG_OUTBAND — an out of band mode is getting used instead (think reading the PHY, that kind of thing) 🙈
• PHYLINK_PCS_NEG_INBAND_DISABLED — inband mode got selected, but autoneg is disabled 😭 sad but valid
• PHYLINK_PCS_NEG_INBAND_ENABLED — inband mode selected and autoneg enabled 🔥 we love a fully turned-on situation

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⭐ NOTE ⭐

heads up bestie: this function is for cases where the PCS itself is involved in negotiation (like Clause 37, SGMII and similar situations 🦋) — it is not for Clause 73. keep that distinction close to your heart, fr fr 💜

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🌈 SEE ALSO 🌈

the whole phylink extended universe, and yes you will be reading all of it 💅 starting with the kernel file ./drivers/net/phy/phylink.c, then struct phylink(9), and the rest of the gang:

• phylink_set_port_modes(9)
• phylink_interface_max_speed(9)
• phylink_caps_to_link_caps(9)
• phylink_caps_to_linkmodes(9)
• phylink_limit_mac_speed(9)
• phylink_cap_from_speed_duplex(9)
• phylink_get_capabilities(9)
• phylink_validate_mask_caps(9)
• phylink_set_fixed_link(9)
• phylink_create(9)
• phylink_destroy(9)
• phylink_expects_phy(9)
• phylink_connect_phy(9)
• phylink_of_phy_connect(9)
• phylink_fwnode_phy_connect(9)
• phylink_disconnect_phy(9)
• phylink_mac_change(9)
• phylink_pcs_change(9)
• phylink_start(9)
• phylink_stop(9)
• phylink_rx_clk_stop_block(9)
• phylink_rx_clk_stop_unblock(9)
• phylink_suspend(9)
• phylink_prepare_resume(9)
• phylink_resume(9)
• phylink_ethtool_get_wol(9)
• phylink_ethtool_set_wol(9)
• phylink_ethtool_ksettings_get(9)
• phylink_ethtool_ksettings_set(9)
• phylink_ethtool_nway_reset(9)
• phylink_ethtool_get_pauseparam(9)
• phylink_ethtool_set_pauseparam(9)
• phylink_get_eee_err(9)
• phylink_ethtool_get_eee(9)
• phylink_ethtool_set_eee(9)
• phylink_mii_ioctl(9)
• phylink_speed_down(9)
• phylink_speed_up(9)
• phylink_decode_usxgmii_word(9)
• phylink_decode_usgmii_word(9)
• phylink_mii_c22_pcs_decode_state(9)
• phylink_mii_c22_pcs_get_state(9)
• phylink_mii_c22_pcs_encode_advertisement(9)
• phylink_mii_c22_pcs_config(9)
• phylink_mii_c22_pcs_an_restart(9)
• phylink_replay_link_begin(9)
• phylink_replay_link_end(9)

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that's the whole page, bestie, you ate that 🍓✨ this cutie lives in ./drivers/net/phy, dated October 2026, and it's brought to you by the Kernel API Manual — phylink_pcs_neg_mode(9) out 💅💖