genphy_c45_r...master_slave(9)

📦 version 7.3.1, in nixpkgs unstable

💅 genphy_c45_read_master_slave — a Kernel API Manual moment

okay so bestie, we are in the Kernel API Manual today and the page is literally called genphy_c45_r...master_slave(9) (yes the title got truncated, she's mysterious like that ✨). anyway. sit down, hydrate, and let's talk about reading master/slave status off a PHY 🦋

✨ NAME ✨

genphy_c45_read_master_slave — read master/slave status 👑

🌸 SYNOPSIS 🌸

int genphy_c45_read_master_slave (struct phy_device *phydev );

🎀 ARGUMENTS 🎀

  • phydev — the target phy_device struct, i.e. the PHY we're snooping on 🕵️‍♀️ this is the main character of the whole function, no cap.

💅 DESCRIPTION 💅

So what does she do? She reads the Master/Slave configuration and status from the 10GBASE-T control/status registers — that's MMD 7, Reg 0x0020 and Reg 0x0021. Both of them. She's thorough like that 🧚

like, that's the whole vibe: go into those two registers and pull out who's the master and who's the slave, plus the status. iconic behavior tbh 💜

🔥 RETURN 🔥

  • 0 on success — slay, we love a clean exit ✨
  • a negative error code on failure — 😭 that's the "something went wrong" case, handle it pls

🌈 SEE ALSO 🌈

bestie there are SO many cousins, okay, she's part of a whole extended family and they all live in the kernel file ./drivers/net/phy/phy-c45.c — here's the entire guest list, not skipping a single one 🫶

ngl that's a lot of cross-references — read them all, iykyk 👀

and that's the page!! 💖 this lil beauty lives in ./drivers/net/phy, she's dated October 2026, and she answers to genphy_c45_r...master_slave(9) — okay bye, go read your registers responsibly 🎀🦋✨

📦 where this page comes from