comedi_open_from(9)

🦋 comedi_open_from(9) — Kernel API Manual 🦋

okay so bestie, this is the Kernel API Manual page for comedi_open_from(9) — the kernel-side COMEDI open situation, and it is very "let me in but also please don't make an infinite loop" 💅✨

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💖 NAME 💖

comedi_open_from — open a COMEDI device from the kernel with loop checks 🎀

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🌸 SYNOPSIS 🌸

       struct comedi_device * comedi_open_from (const char *filename , int from
       );

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🎀 ARGUMENTS 🎀

• filename — a fake pathname, of the form "/dev/comediN" 🦋
• from — the device number it is being opened from (if it's in range) 🫶

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🔥 DESCRIPTION 🔥

so the move is: filename gets converted to a COMEDI device number, and then it gets “opened” — but only if it exists and is attached to a low-level COMEDI driver, iykyk ✨

if from is in range, it will refuse to open the device whenever doing so would form a loop of devices opening each other 😭 that's the loop check doing its main character thing 💅

also there is a limit of 255 on the number of concurrent opens from one device to another. periodt. 🍓

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⭐ RETURN ⭐

• success — a pointer to the COMEDI device 👑
• failure — NULL 💀

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/comedi/kcomedilib/kcomedilib_main.c 📁
• comedi_close_from(9) 🫶

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mwah 💖 that's the page from source ./drivers/comedi/kcomedilib, dated October 2026, for comedi_open_from(9). stay loop-free, bestie 🌸💅