comedi_timeout(9)

💖 comedi_timeout — busy-wait for a driver condition to occur ✨

okay so bestie, welcome to comedi_timeout(9), straight out of the Kernel API Manual 💅 this one's a little helper that just... waits. patiently. for a condition to show up. iconic behavior honestly 🫶

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✨ SYNOPSIS ✨

int comedi_timeout (struct comedi_device *dev , struct comedi_subdevice
*s , struct comedi_insn *insn , int (*cb)(struct comedi_device *dev,
struct comedi_subdevice *s, struct comedi_insn *insn, unsigned long
context) , unsigned long context );

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🎀 ARGUMENTS 🎀

• dev — the COMEDI device, bestie. the whole vibe.
• s — the COMEDI subdevice. the little side character that matters.
• insn — the COMEDI instruction. what we're out here doing.
• cb — the callback that checks whether the condition has happened yet. this is the main character fr fr 👑
• context — private context, passed in from the driver. the driver's own little secret 🍓

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🌸 DESCRIPTION 🌸

so basically it busy-waits for up to a second (COMEDI_TIMEOUT_MS, that's the cap, no cap) waiting for the condition — or for some error other than -EBUSY — to occur 💀

the parameters dev, s, insn, and context get passed straight to the callback function, and that callback returns -EBUSY to keep waiting, or literally any other value to stop waiting (generally 0 if the condition occurred, or some error value). that's it, that's the whole loop 🌈

Returns -ETIMEDOUT if it timed out 😭 otherwise you just get whatever the callback function returned. periodt.

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🦋 SEE ALSO 🦋

Kernel file ./drivers/comedi/drivers.c plus this whole friend group:

• comedi_set_hw_dev(9)
• comedi_alloc_devpriv(9)
• comedi_alloc_subdevices(9)
• comedi_alloc_subdev_readback(9)
• comedi_readback_insn_read(9)
• comedi_dio_insn_config(9)
• comedi_dio_update_state(9)
• comedi_bytes_per_scan_cmd(9)
• comedi_bytes_per_scan(9)
• comedi_nscans_left(9)
• comedi_nsamples_left(9)
• comedi_inc_scan_progress(9)
• comedi_handle_events(9)
• comedi_load_firmware(9)
• __comedi_check_request_region(9)
• comedi_check_request_region(9)
• comedi_legacy_detach(9)
• comedi_auto_config(9)
• comedi_auto_unconfig(9)
• comedi_driver_register(9)
• comedi_driver_unregister(9)

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ngl this page came from ./drivers/comedi, dated October 2026 — mwah, sending u a kiss, go poll some hardware responsibly 💜💋