xe_mmio_wait32_not(9)

📦 version 7.3.1, in nixpkgs unstable

💅 xe_mmio_wait32_not(9) — the kernel API manual, bestie edition 💅

okay so real talk, this is a page from the Kernel API Manual and it's about one very specific little function that will wait around for a register to stop being a certain vibe. sit down, get a snack, we're learning 🍓

✨ NAME ✨

xe_mmio_wait32_not — literally just: wait for a register to return anything other than the given masked value. that's it. that's the whole job. she's a "not equal to" girlie 💅

🎀 SYNOPSIS 🎀

int xe_mmio_wait32_not (struct xe_mmio *mmio , struct xe_reg reg , u32
mask , u32 val , u32 timeout_us , u32 *out_val , bool atomic );

that's the whole signature, no cap. seven parameters, one int back. write it exactly like that or the compiler will simply end you 😭

🦋 ARGUMENTS 🦋

okay bestie, let's do the roll call, one by one, nobody gets skipped:

  • mmio — the MMIO target 💖 this is where we're poking, mmkay?
  • reg — the register to read value from. the actual spot we're watching like it's a reality show 🌸
  • mask — mask to be applied to the value read from the register. we're filtering, we're selecting, we're doing a little bitwise moment ✨
  • val — the value not to be matched, after applying the mask. so like, if it does match this, we keep waiting. we do NOT want this one 🙈
  • timeout_us — time out after this period of time. yeah. she's got a deadline and she will enforce it ⏰
  • out_val — if not NULL, points where to store the last unmasked value. so you can peep what the register was actually saying at the end 👀
  • atomic — needs to be true if calling from an atomic context. absolutely non-negotiable, do not lie to her about this one 💀

🌈 DESCRIPTION 🌈

so here's the tea: this function works exactly like xe_mmio_wait32, with the one (1) exception that val is expected not to be matched.

that's the entire plot twist. same energy, same behaviour, just inverted on the match. the way that one flipped condition changes everything, honestly iconic 🔥

👑 SEE ALSO 👑

like, go read these next, i'm begging 🫶:

and that's the whole page, bestie, you ate that 💖 this came to you from ./drivers/gpu/drm/xe, dated October 2026, and she answers to the name xe_mmio_wait32_not(9) 🎀✨🦋

📦 where this page comes from