parport_wait_peripheral(9)

✨ parport_wait_peripheral ✨

okay so this is a page from the Kernel API Manual and it's about parport_wait_peripheral — a function that literally just waits for status lines to change, but only for like 35ms max. she's patient but not that patient 💅

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🌸 NAME 🌸

parport_wait_peripheral — wait for status lines to change in 35ms

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🎀 SYNOPSIS 🎀

int parport_wait_peripheral (struct parport *port , unsigned char mask ,
       unsigned char result );

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🦋 ARGUMENTS 🦋

• port — the port you're watching 👀 like your main character, the one we keep an eye on
• mask — which status lines to watch, bestie. this is your "these bits matter" situation
• result — the desired values of the chosen status lines — i.e. what you want those watched bits to be, periodt

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💖 DESCRIPTION 💖

okay so here's the vibe: this function waits until the masked status lines have the desired values, OR until 35ms have elapsed — whichever comes first, no cap. (and if you're wondering why 35ms specifically, the manpage says to look at IEEE 1284-1994 page 24 to 25 for why this value in particular is hardcoded. it's giving legacy lore 📜)

the mask and result parameters are bitmasks, with the bits defined by the constants in parport.h: PARPORT_STATUS_BUSY, and so on. iykyk.

the port is polled quickly to start off with, in anticipation of a fast response from the peripheral — like she's eager, she's checking constantly at first 🏃‍♀️💨. this fast polling time is configurable (using /proc), and defaults to 500usec. so yes, configurable, 500usec default, write it down.

⚠️ important caveat time: if the timeout for this port (see parport_set_timeout) is zero, the fast polling time is 35ms, and this function does not call schedule. not me pointing out that this means it's busy waiting — zero timeout means zero sleeping 😴

if the timeout for this port is non-zero, after the fast polling fails it uses parport_wait_event to wait for up to 10ms, waking up if an interrupt occurs. so she naps, but only 10ms max, and she's light-sleeping — interrupt = immediate wake-up ⏰✨

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/parport/ieee1284.c
• parport_wait_event(9)
• parport_poll_peripheral(9)
• parport_negotiate(9)
• parport_write(9)
• parport_read(9)
• parport_set_timeout(9)

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🫶 bestie, that's the whole thing. this page came from ./drivers/parport, dated October 2026 — so when you see the footer, just know it's the version info from the source, and she said what she said. slay. 💅✨