n_tty_poll(9)

n_tty_poll(9) — poll method for N_TTY, from the Kernel API Manual ✨

🌸 NAME 🌸

n_tty_poll — the poll method for N_TTY, periodt. 💅 This is the function that shows up when the line discipline needs its poll moment, and yes bestie, we’re in the Kernel API Manual now. 🎀

✨ SYNOPSIS ✨

Okay so the signature is giving exactly this, no cap:

__poll_t n_tty_poll (struct tty_struct *tty , struct file *file ,
       poll_table *wait );

🎀 ARGUMENTS 🎀

• tty — the terminal device, aka the main character of this call 🖥️💖
• file — the file that’s accessing it, no cap 📁
• wait — the poll table, literally the waiting room 🧾✨

💜 DESCRIPTION 💜

Okay so picture this: the line discipline gets asked to poll for data or for special events, and this function is the one that answers the call. ✨

Important caveat, bestie: this code is not serialized with respect to other events save open/close. Open/close is the only exception, so don’t assume everything is out here neatly taking turns. 😭

And this code must be sure never to sleep through a hangup — like, never ever, not even a little nap. 💀 That’s the whole vibe: no sleeping through a hangup, fr fr.

Locking: called without the kernel lock held -- fine. Slay. 🫶

🦋 SEE ALSO 🦋

Kernel file ./drivers/tty/n_tty.c is the source spot, and here’s the entire squad — every single reference, no skips, iykyk:

• n_tty_kick_worker(9)
• n_tty_write_wakeup(9)
• put_tty_queue(9)
• reset_buffer_flags(9)
• n_tty_flush_buffer(9)
• is_utf8_continuation(9)
• is_continuation(9)
• do_output_char(9)
• process_output(9)
• process_output_block(9)
• __process_echoes(9)
• add_echo_byte(9)
• echo_move_back_col(9)
• echo_set_canon_col(9)
• echo_erase_tab(9)
• echo_char_raw(9)
• echo_char(9)
• finish_erasing(9)
• eraser(9)
• isig(9)
• n_tty_receive_break(9)
• n_tty_receive_overrun(9)
• n_tty_receive_parity_error(9)
• n_tty_receive_char_flow_ctrl(9)
• n_tty_receive_char(9)
• n_tty_receive_buf_common(9)
• n_tty_set_termios(9)
• n_tty_close(9)
• n_tty_open(9)
• copy_from_read_buf(9)
• canon_copy_from_read_buf(9)
• job_control(9)
• n_tty_read(9)
• n_tty_write(9)
• n_tty_inherit_ops(9)

Source/version vibes: ./drivers/tty · October 2026 · n_tty_poll(9) 💖 byeee bestie, go poll responsibly ✨