COMEDI_POLL(3)

✨ COMEDI_POLL ✨

okay bestie, we're in the Comedi reference section, third page, and this one is comedi_poll 💅 it's short, it's sweet, and it's giving "wake up the buffer" energy. let's go 🦋

---

🌸 NAME 🌸

comedi_poll — force updating of streaming buffer 🔥

---

🎀 SYNOPSIS 🎀

#include <comedilib.h>

int comedi_poll(comedi_t * device, unsigned int subdevice);

---

💜 DESCRIPTION 💜

so here's the vibe: you call comedi_poll on a subdevice that already has a Comedi command in progress, and its whole job is to update the streaming buffer. like, poke it. nudge it. refresh it. ✨

if the driver supports it (and honestly, only a few Comedi drivers do 🙈), then all the available samples get copied into the streaming buffer. those samples might be chilling in DMA buffers, or just hanging out in device FIFOs, waiting for their moment. and comedi_poll is the one who comes and collects them. main character behavior fr fr 👑

lowkey important: only a few Comedi drivers support this operation. so if yours doesn't, that's not a you problem, that's just the driver's vibe check failing. no cap.

---

⭐ RETURN VALUE ⭐

• on success — comedi_poll returns the number of additional bytes available 💖
• on failure — it returns -1 😭

---

👑 AUTHORS 👑

• David Schleef <ds@schleef.org> — Author.
• Frank Mori Hess <fmhess@users.sourceforge.net> — Author.
• Herman Bruyninckx <Herman.Bruyninckx@mech.kuleuven.ac.be> — Author.
• Bernd Porr <tech@linux-usb-daq.co.uk> — Author.
• Ian Abbott <abbotti@mev.co.uk> — Author.
• Éric Piel <piel@delmic.com> — Author.

(not one, not two, but six authors. the way that collaboration ate 🫶 collab goals honestly.)

---

🎀 COPYRIGHT 🎀

Copyright © 1998-2003 David Schleef
Copyright © 2001-2003, 2005, 2008 Frank Mori Hess
Copyright © 2002-2003 Herman Bruyninckx
Copyright © 2012 Bernd Porr
Copyright © 2012 Ian Abbott
Copyright © 2012, 2015 Éric Piel

This document is part of Comedilib. In the context of this document, the term "source code" as defined by the license is interpreted as the XML source.

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, version 2.1 of the License.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

okay legal bestie moment, but fr fr: NO WARRANTY, read the LGPL, it's all there, don't skip it 💀

---

aaaand that's the page!! 🌈 this lil guy lives in the Comedi manual, page COMEDI_POLL(3), dated 03/20/2026 — and that's a wrap, stay slay, go poll your subdevices responsibly 💅💖✨