ytphy_modify_ext(9)

📦 version 7.3.1, in nixpkgs unstable

💅 ytphy_modify_ext — the Kernel API Manual tea 🫖

okay bestie, welcome to the ytphy_modify_ext(9) page — it's a kernel API manual situation and honestly it's kind of a cute little one ✨

🎀 NAME 🎀

ytphy_modify_ext — bits-modify a PHY's extended register. that's it, that's the whole vibe 💅

🌸 SYNOPSIS 🌸

int ytphy_modify_ext (struct phy_device *phydev , u16 regnum , u16 mask
, u16 set );

like, look at her go 😭 she's giving "small function, big responsibility" fr fr

🦋 ARGUMENTS 🦋

  • phydev — a pointer to a struct phy_device. yes girl, the whole PHY, right there 👑
  • regnum — the register number to write. which register are we touching? this one 📍
  • mask — bit mask of bits to clear. the "bye bye" list 💀
  • set — bit mask of bits to set. the "hello gorgeous" list 🫶

⭐ NOTE ⭐

okay so this is a convenience function (iconic, low-effort, high-reward) that lets you modify a PHY's extended register, and the math is literally:

new register value = (old register value & ~mask) | set

read it like a recipe: take the old value, AND it with the inverse of mask to wipe those bits out, then OR in set to light up the ones you want. chef's kiss 🧚

🚨 big important caveat, do NOT skip this one bestie: the caller must have taken the MDIO bus lock. like, must. no cap. that's on you, not on her.

and she returns 0 or a negative error code — so zero is the slay outcome, negative means something went sideways 😭

🌈 SEE ALSO 🌈

the whole friend group, no one left out 💖 and yeah, the kernel file lives at ./drivers/net/phy/motorcomm.c, go say hi 🎀

and that's the page, bestie 🫶 this little gem lives in ./drivers/net/phy, dated October 2026 — go off, read some more manpages, and remember: take the lock. periodt. 💜

📦 where this page comes from