gsm_dlci_t1(9)

💅 gsm_dlci_t1(9) — T1 timer expiry

okay bestie, welcome to the Kernel API Manual page for gsm_dlci_t1(9) — yes, the T1 timer expiry girlie herself. This is the whole lore, no skips, no cap. ✨

🌸 NAME 🌸

gsm_dlci_t1 — T1 timer expiry. literally the whole vibe. 🎀

📟 SYNOPSIS 📟

void gsm_dlci_t1 (struct timer_list *t );

🎀 ARGUMENTS 🎀

• t — timer contained in the DLCI that opened. that's the timer sitting inside the DLCI that opened, periodt. 🫶

🦋 DESCRIPTION 🦋

The T1 timer handles retransmits of control frames — essentially SABM and DISC. it's giving retransmit main character energy. 🔥

We resend the command until the retry count runs out. If that retry count does run out, an opening port goes back to closed, and a closing port is simply put into closed state. Any further frames from the other end will get a DM response. 😭

Some control dlci can stay in ADM mode with other dlci working just fine. In that case we can just keep the control dlci open after the DLCI_OPENING receives DM. lowkey iconic behavior. 💅

🌈 SEE ALSO 🌈

Kernel file: ./drivers/tty/n_gsm.c — and the whole extended fam:

• gsm_fcs_add(9), gsm_fcs_add_block(9), gsm_read_ea(9), gsm_read_ea_val(9), gsm_encode_modem(9), gsm_encode_params(9), gsm_register_devices(9), gsm_unregister_devices(9)
• gsm_print_packet(9), gsm_stuff_frame(9), gsm_send(9), gsm_dlci_clear_queues(9), gsm_response(9), gsm_command(9), gsm_data_alloc(9), gsm_send_packet(9)
• gsm_is_flow_ctrl_msg(9), gsm_data_kick(9), __gsm_data_queue(9), gsm_data_queue(9), gsm_dlci_data_output(9), gsm_dlci_data_output_framed(9), gsm_dlci_modem_output(9), gsm_dlci_data_sweep(9), gsm_dlci_data_kick(9)
• gsm_control_command(9), gsm_control_reply(9), gsm_process_modem(9), gsm_process_negotiation(9), gsm_control_modem(9), gsm_control_negotiation(9), gsm_control_rls(9), gsm_control_message(9)
• gsm_control_response(9), gsm_control_keep_alive(9), gsm_control_transmit(9), gsm_control_retransmit(9), gsm_control_send(9), gsm_control_wait(9), gsm_dlci_close(9), gsm_dlci_open(9)
• gsm_dlci_negotiate(9), gsm_dlci_begin_open(9), gsm_dlci_set_opening(9), gsm_dlci_set_wait_config(9), gsm_dlci_begin_close(9), gsm_dlci_data(9), gsm_dlci_command(9), gsm_kick_timer(9)
• gsm_dlci_copy_config_values(9), gsm_dlci_config(9), gsm_dlci_alloc(9), gsm_dlci_free(9), gsm_dlci_release(9), gsm_queue(9), gsm0_receive_state_check_and_fix(9), gsm0_receive(9)
• gsm1_receive_state_check_and_fix(9), gsm1_receive(9), gsm_error(9), gsm_cleanup_mux(9), gsm_activate_mux(9), gsm_free_mux(9), gsm_free_muxr(9), gsm_alloc_mux(9)
• gsmld_output(9), gsmld_write_trigger(9), gsmld_write_task(9), gsmld_attach_gsm(9), gsmld_detach_gsm(9), gsmld_flush_buffer(9), gsmld_close(9), gsmld_open(9)
• gsmld_write_wakeup(9), gsmld_read(9), gsmld_write(9), gsmld_poll(9), gsm_modem_upd_via_data(9), gsm_modem_upd_via_msc(9), gsm_modem_update(9), gsm_wait_modem_change(9)

mwah 💋 this page is brought to you by source/version ./drivers/tty, dated October 2026, and it's still gsm_dlci_t1(9) forever. periodt. 🫶✨