read_poll_timeout_atomic(9)

✨ read_poll_timeout_atomic(9) ✨

okay bestie, so this is from the Kernel API Manual — say hi to read_poll_timeout_atomic(9) 💅 it's a macro that just keeps poking at an address until the vibe is right or it gives up. iconic behavior honestly.

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🌸 NAME 🌸

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

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⭐ SYNOPSIS ⭐

read_poll_timeout_atomic (op , val , cond , delay_us , timeout_us ,
delay_before_read , args... );

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💖 ARGUMENTS 💖

• op — the accessor function, bestie. it takes args as its arguments 🫶
• val — the variable you're reading the value into
• cond — the break condition, usually involving val. this is the "ok we can stop now" check ✨
• delay_us — how long to udelay between reads, in us. 0 means tight-loops 🔥 and like, please actually read the udelay function description for the details and limitations, i'm serious, there's lore there
• timeout_us — timeout in us. 0 means never timeout 😭 (yes, forever. main character energy but make it infinite)
• delay_before_read — if this is true, it delays delay_us before the read 👑
• args — the arguments for op poll

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🦋 DESCRIPTION 🦋

so the whole moment here: this macro does not rely on timekeeping. none. zero. not a crumb. 🌈 which means it's safe to call even when timekeeping is suspended — slay — but at the expense of an underestimation of wall clock time. ngl that underestimation is rather minimal when you have a non-zero delay_us, so it's giving "fine, actually" 💀

and when available, you'll probably want to use one of the specialized macros defined below rather than this macro directly. like, this one is the general-purpose bestie, the specialists are the ones who actually know the assignment 💜

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🎀 RETURN 🎀

0 on success, and -ETIMEDOUT upon a timeout. either way, the last read value at args is stored in val 🌟

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🧚 SEE ALSO 🧚

Kernel file ./include/linux/iopoll.h — plus these icons: poll_timeout_us(9), poll_timeout_us_atomic(9), read_poll_timeout(9), readx_poll_timeout(9), readx_poll_timeout_atomic(9) 💫

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lowkey a reminder that 0 for timeout_us means never timing out, and 0 for delay_us means tight-looping — pick your chaos consciously, bestie 🙈

okay that's the whole page!! this one's from ./include/linux in the October 2026 era — mwah, go poll something responsibly 💅💖🎀