mdiobus_modify_changed(9)

📦 version 7.3.1, in nixpkgs unstable

✨ mdiobus_modify_changed ✨

okay so bestie, quickest vibe check ever: this is the mdiobus_modify_changed page from the Kernel API Manual, and it's basically the "did anything actually change tho?" helper for tweaking an mdio device register. Read-modify-write but it tells you if it did anything. Obsessed. 💅

🎀 NAME 🎀

mdiobus_modify_changed — a convenience function for modifying a given mdio device register and returning whether it changed. literally its whole personality. no cap. 💖

🦋 SYNOPSIS 🦋

int mdiobus_modify_changed (struct mii_bus *bus , int addr , u32 regnum
, u16 mask , u16 set );

five arguments, one very important return value, we love to see it ✨

🌸 ARGUMENTS 🌸

  • bus — the mii_bus struct. the main character of this whole operation 🫶
  • addr — the phy address. where your fave lives, basically
  • regnum — the register number to write. the exact spot we're touching ✨
  • mask — the bit mask of bits to clear. bye-bye bits 👋
  • set — the bit mask of bits to set. hello bits 🎀

🌈 RETURN 🌈

  • 1 — the register was modified (slay, something happened 🔥)
  • 0 — no change was needed (nothing to do, honestly valid 💀)
  • negative — any error condition (not the vibe, but at least it told you 😭)

👑 SEE ALSO 👑

Kernel file ./drivers/net/phy/mdio_bus.c and its whole friend group:

all iconic, all worth a read, iykyk 🧚💜

okay and that's the whole page bestie — go forth and check your registers 🦋💖

<div align="center">🌸 from <code>./drivers/net/phy</code>, dated <strong>October 2026</strong> — mwah, see u in the kernel tree 🎀💅</div>

📦 where this page comes from