phy_caps_lookup_by_linkmode(9)

✨ phy_caps_lookup_by_linkmode ✨

okay so bestie, welcome to the phy_caps_lookup_by_linkmode(9) era — it's a kernel API manual page and honestly it's giving "small function, big main character energy" 💅 Let's get into it.

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💖 NAME 💖

phy_caps_lookup_by_linkmode — look up the fastest matching link_capabilities 🏎️✨

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🦋 SYNOPSIS 🦋

const struct link_capabilities * phy_caps_lookup_by_linkmode (const
       unsigned long *linkmodes );

so it takes a pointer to some linkmodes and hands you back a const struct link_capabilities * — no cap, that's the whole vibe 🎀

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🌸 ARGUMENTS 🌸

• linkmodes — the linkmodes you wanna match against 💫 that's literally it, that's the whole argument, she's lowkey uncomplicated.

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🎀 RETURN 🎀

It returns the highest-speed link_capabilities that intersects the given linkmodes 🔥 like, fastest wins, periodt.

And here's the cute little tiebreaker detail, iykyk: in case several DUPLEX_ options exist at that speed, DUPLEX_FULL is matched first 👑 so full duplex gets first dibs at that speed level.

If there's no match at all? You get NULL back 😭 not me getting rejected by a lookup function. fr fr, no match means NULL.

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🌈 SEE ALSO 🌈

Kernel file ./drivers/net/phy/phy_caps.c — go read the source, bestie, it's right there 🫶

• phy_caps_init(9)
• phy_caps_speeds(9)
• phy_caps_lookup_by_linkmode_rev(9)
• phy_caps_lookup(9)
• phy_caps_linkmode_max_speed(9)
• phy_caps_valid(9)
• phy_caps_linkmodes(9)
• phy_caps_from_interface(9)
• phy_caps_medium_get_supported(9)
• phy_caps_mediums_from_linkmodes(9)

that's the whole friend group, go say hi to all of them 💜

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annnnd that's the page!! brought to you by ./drivers/net/phy 🌟 dated October 2026 — a whole little time capsule, iconic of her honestly. hope this helped bestie, mwah 💋✨🍓