xe_mmio_wait32(9)

💅 xe_mmio_wait32(9) — Kernel API Manual

okay so bestie, welcome to the Kernel API Manual page for xe_mmio_wait32(9). This is the little poller that keeps checking a register until the masked value matches what you want, and it’s lowkey iconic. No cap, we’re keeping every argument, value, caveat, and reference exactly as it is. 🫶

🌸 NAME 🌸

xe_mmio_wait32 — Wait for a register to match the desired masked value ✨

🎀 SYNOPSIS 🎀

the way that signature goes, fr fr:

int xe_mmio_wait32 (struct xe_mmio *mmio , struct xe_reg reg , u32 mask
       , u32 val , u32 timeout_us , u32 *out_val , bool atomic );

💅 ARGUMENTS 💅

• mmio — MMIO target. Yep, that’s the target, periodt. 💖
• reg — register to read value from. The register we’re reading from, obviously. 👑
• mask — mask to be applied to the value read from the register. It gets applied to whatever value we read from the register, ngl. 💅
• val — desired value after applying the mask. That’s the value we want after the mask does its thing. ✨
• timeout_us — time out after this period of time. Wait logic tries to be smart, applying an exponential backoff until timeout_us is reached. 🕰️
• out_val — if not NULL, points where to store the last unmasked value. If it’s not NULL, this is where that last unmasked value gets stored. 🎀
• atomic — needs to be true if calling from an atomic context. If you’re calling from an atomic context, this needs to be true, bestie. ⚡

✨ DESCRIPTION ✨

This function polls for the desired masked value and returns zero on success or -ETIMEDOUT if timed out. Like, it keeps checking until it gets the masked value it wants, and if it times out you get -ETIMEDOUT. 💀

okay but the timeout caveat is important, bestie: timeout_us represents the minimum amount of time to wait before giving up. The actual time taken by this function can be a little more than timeout_us for different reasons, specially in non-atomic contexts. Thus, it is possible that this function succeeds even after timeout_us has passed. No cap, that’s literally how it’s documented. 😭

🦋 SEE ALSO 🦋

• Kernel file ./drivers/gpu/drm/xe/xe_mmio.c
• xe_mmio_probe_tiles(9)
• xe_mmio_probe_early(9)
• xe_mmio_init(9)
• xe_mmio_read64_2x32(9)
• xe_mmio_wait32_not(9)
• xe_mmio_init_vf_view(9)

that’s the whole page, bestie! sourced from ./drivers/gpu/drm/xe in the Kernel API Manual, dated October 2026. xe_mmio_wait32(9) out — stay hydrated and may your registers match on the first poll 💖✨🎀