readx_poll_timeout(9)

💅 readx_poll_timeout 💅

okay so this is a Kernel API Manual page, and bestie, it's literally about polling an address over and over until a condition hits or you run out of time. no cap. ⏰

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✨ NAME ✨

readx_poll_timeout — periodically poll an address until a condition is met or a timeout occurs 🎀

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🌸 SYNOPSIS 🌸

readx_poll_timeout (op , addr , val , cond , sleep_us , timeout_us );

like, yes, that's the whole thing. six args. she's iconic. 💅

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🦋 ARGUMENTS 🦋

• op — the accessor function, aka the little guy who does the actual reading (it takes addr as its only argument, that's the whole vibe)
• addr — the address you're polling, the main character of this whole operation 👑
• val — the variable where the value gets read into 🫶
• cond — the break condition, the thing you're waiting for (usually involves val, iykyk)
• sleep_us — max time to sleep between reads, in us. and yes, 0 means tight-loops 😭 please go read the usleep_range function description for the details and limitations, fr fr, don't skip it
• timeout_us — the timeout, in us. 0 means never timeout, so like... she'll wait forever, no thoughts head empty 💀

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🧚 DESCRIPTION 🧚

so bestie, when it's available, you'll probably want to use one of the specialized macros defined below instead of this macro directly. that's the whole tea. ☕✨

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⭐ RETURN ⭐

0 on success, and -ETIMEDOUT when the timeout hits. either way, the last read value at addr gets stored in val, so you're never left hanging with nothing. 💖

lowkey important warning: this must not be called from atomic context if sleep_us or timeout_us are used. like, do not do that. 🙈

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🌈 SEE ALSO 🌈

• the kernel file ./include/linux/iopoll.h — go look at it 👀
• poll_timeout_us(9)
• poll_timeout_us_atomic(9)
• read_poll_timeout(9)
• read_poll_timeout_atomic(9)
• readx_poll_timeout_atomic(9)

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and that's the page, bestie! this one lives in ./include/linux, dated October 2026 — so mark your calendars, the kernel API manual is booked and busy. 🎀💜✨