ata_wait_register(9)

📦 version 7.3.1, in nixpkgs unstable

💖 ata_wait_register(9) — the "wait until the register changes" page 💖

okay so this is a page from the Kernel API Manual, bestie — it's ata_wait_register(9), and honestly it's giving "just sit there and poll until something happens" energy. Let's get into it ✨

🌸 NAME 🌸

ata_wait_register — wait until register value changes

like, literally the whole job. you vibe. you wait. the register eventually changes. 💅

🎀 SYNOPSIS 🎀

u32 ata_wait_register (struct ata_port *ap , void __iomem *reg , u32
mask , u32 val , unsigned int interval , unsigned int timeout );

yes, that's the whole signature, line break and all — no cap 🫶

🦋 ARGUMENTS 🦋

here's the cast of characters, one by one:

  • ap — the ATA port whose register we're waiting on. plot twist: it can be NULL 🙈
  • reg — the IO-mapped register. the thing we keep peeking at 👀
  • mask — the mask you slap onto the read register value before testing
  • val — the wait condition (aka the thing we're comparing against)
  • interval — polling interval, in milliseconds ⏱️
  • timeout — timeout, in milliseconds. the "okay we're done waiting" deadline 💀

✨ DESCRIPTION ✨

so here's the tea: waiting for some bits of a register to change is a super common operation for ATA controllers — like, it's their whole personality at this point.

this function reads the 32bit LE IO-mapped register reg and tests for this exact condition:

(*reg & mask) != val

if the condition is met, it returns — slay, we're out 💅 otherwise, the process is repeated after interval_msec until timeout. yes bestie, it keeps going. that's the point. 🔁

LOCKING: Kernel thread context (may sleep) 😴 — so keep that in mind, because sleeping where you shouldn't is not the vibe 💀

👑 RETURN 👑

The final register value. that's it, that's the return. the value at the end of the saga 🫶

🌈 SEE ALSO 🌈

here's the whole friend group — Kernel file ./drivers/ata/libata-core.c plus these icons, in order, no skips, no cuts 🔥

like, that's the entire group chat. iykyk 💜

and that's the page!! 🧚

cute little sign-off before you go: this one lives in the kernel source file ./drivers/ata/libata-core.c, it's filed under ./drivers/ata, the manual is dated October 2026, and the page itself is ata_wait_register(9) — so next time your register refuses to change, you know exactly who to call 💅🎀

📦 where this page comes from