mac_select_pcs(9)

💅 mac_select_pcs(9) — like, the Kernel API Manual girlies know

Okay so bestie, welcome to mac_select_pcs(9). Yes the manual name is literally part of the whole brand — it's a Kernel API Manual situation and we're about to read it together. Grab a strawberry drink 🍓, this one's short but she matters.

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✨ NAME ✨

mac_select_pcs — pick a PCS for the interface mode. That's it. That's the whole job. 👑

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🦋 SYNOPSIS 🦋

struct phylink_pcs * mac_select_pcs (struct phylink_config *config ,
phy_interface_t interface );

Look at her go. One function, two arguments, zero drama (well, okay, some drama if you return an error pointer, more on that below 😭).

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🎀 ARGUMENTS 🎀

• config — a pointer to a struct phylink_config. Yeah. That thing. You know her.
• interface — the PHY interface mode you're getting a PCS for. The vibe check in type form.

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🔥 DESCRIPTION 🔥

So what does she actually do? She returns the struct phylink_pcs for the specified interface mode. That's the main character move.

But wait, there's range:

• If none is required, she returns NULL. Respect. Sometimes the answer is nobody. 🙈
• On error, she returns an error pointer. Not me crying in IS_ERR() 💀

Genuinely important caveat, no cap: this function must not modify any state. Like, at all. It's a query, bestie, not a mutation. Do not touch. Do not rearrange the furniture. It exists purely to ask "which PCS should be used?"

And here's why that matters — Phylink uses it in two places:

1. During validation, to make sure the configuration is valid. She's checking your fit before you leave the house. 💅
2. When setting a configuration, to internally set the PCS that will actually be used. Slay. That's the assignment.

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🌈 SEE ALSO 🌈

The whole friend group, honestly. Go say hi:

• Kernel file ./include/linux/phylink.h
• struct phylink_link_state(9)
• struct phylink_config(9)
• struct phylink_mac_ops(9)
• mac_get_caps(9)
• mac_prepare(9)
• mac_config(9)
• mac_finish(9)
• mac_link_down(9)
• mac_link_up(9)
• mac_disable_tx_lpi(9)
• mac_enable_tx_lpi(9)
• mac_wol_set(9)
• struct phylink_pcs(9)
• struct phylink_pcs_ops(9)
• pcs_validate(9)
• pcs_inband_caps(9)
• pcs_enable(9)
• pcs_disable(9)
• pcs_get_state(9)
• pcs_config(9)
• pcs_an_restart(9)
• pcs_link_up(9)
• pcs_disable_eee(9)
• pcs_enable_eee(9)
• pcs_pre_init(9)
• phylink_get_link_timer_ns(9)
• phylink_mac_implements_lpi(9)

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🫶 That's the page, bestie. No state was modified in the making of this manpage.

And a cute little sign-off for the credits stans: this one lives under ./include/linux, and the version/date stamp is October 2026 — mac_select_pcs(9), as iconic as ever. 💖✨