phy_set_max_speed(9)

📦 version 7.3.1, in nixpkgs unstable

💅 phy_set_max_speed 💅

okay so this is a page from the Kernel API Manual bestie, and it's about phy_set_max_speed — literally the function that tells your PHY what its speed ceiling is 🎀

✨ NAME ✨

phy_set_max_speed — set the maximum speed the PHY should support 👑

🦋 SYNOPSIS 🦋

void phy_set_max_speed (struct phy_device *phydev , u32 max_speed );

no cap, that's the whole signature 🫶

🌸 ARGUMENTS 🌸

  • phydev — the phy_device struct, aka the main character of this whole operation 💖
  • max_speed — the maximum speed, periodt 🔥

🌈 DESCRIPTION 🌈

okay so picture this: the PHY might be more capable than the MAC 😭 like, the PHY is out here with main character energy and the MAC is just... there. The example the page gives: a Fast Ethernet is connected to a 1G PHY. iconic mismatch honestly 💀

So this function lets the MAC indicate its maximum speed, and so limit what the PHY will advertise ✨ like bestie, please don't go around advertising speeds we can't actually handle 🙈

👑 SEE ALSO 👑

kernel file ./drivers/net/phy/phy-core.c — and here's the whole friend group, all in (9):

slay, that's a lot of links but we're not skipping a single one 🧚

ngl bestie, read the whole list — iykyk 💜

and that's the tea 🍓 this came out of ./drivers/net/phy back in October 2026, so shoutout to the kernel peeps for keeping it cute and documented 💖✨ mwah, bye! 🎀

📦 where this page comes from