usb_serial_generic_write(9)

💖 usb_serial_generic_write(9) 💖

okay so bestie, welcome to the Kernel API Manual page for usb_serial_generic_write — literally the generic write function and the moment your USB-serial port finally gets to say something 🗣️✨

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🌸 NAME 🌸

usb_serial_generic_write — the generic write function, no cap 🫶

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🎀 SYNOPSIS 🎀

int usb_serial_generic_write (struct tty_struct *tty , struct
usb_serial_port *port , const unsigned char *buf , int count );

like, that's the whole signature, character for character, mwah 💅

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🦋 ARGUMENTS 🦋

• tty — the tty for the port 👑 this is the terminal-side bestie
• port — the usb-serial port 🌈 the actual hardware vibe
• buf — the data to write 🍓 everything you wanna yeet out the door
• count — the number of bytes to write 🔥 how much of buf we're actually sending

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⭐ RETURN ⭐

The number of characters buffered — and bestie, it "may be anything from zero to count", so don't assume you got all of them, fr fr — or a negative errno value if things went sideways 😭

so like: 0 to count means success-ish (count how many actually got buffered), negative means error. no in-between nonsense, periodt 💀

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💜 SEE ALSO 💜

• Kernel file ./drivers/usb/serial/generic.c 📁
• usb_serial_generic_write_start(9) ✨
• usb_serial_handle_dcd_change(9) 🌸

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and that's the whole page, diva — go forth and buffer some bytes 🧚💖

shoutout to ./drivers/usb/serial, October 2026, and the one and only usb_serial_generic_write(9) — iconic, no notes 👑🎀