drivers/tty/n_hdlc.c

File Facts

System

Linux kernel

Corpus path

drivers/tty/n_hdlc.c

Extension

.c

Size

22345 bytes

Lines

810

Domain

Driver Families

Bucket

drivers/tty

Inferred role

Driver Families: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/init.h
• linux/kernel.h
• linux/sched.h
• linux/types.h
• linux/fcntl.h
• linux/interrupt.h
• linux/ptrace.h
• linux/poll.h
• linux/in.h
• linux/ioctl.h
• linux/slab.h
• linux/tty.h
• linux/errno.h
• linux/string.h
• linux/signal.h
• linux/if.h
• linux/bitops.h
• linux/uaccess.h
• tty.h

Detected Declarations

• struct n_hdlc_buf
• struct n_hdlc_buf_list
• struct n_hdlc
• function flush_rx_queue
• function flush_tx_queue
• function n_hdlc_free_buf_list
• function n_hdlc_tty_close
• function n_hdlc_tty_open
• function frame
• function n_hdlc_tty_write_work
• function n_hdlc_tty_wakeup
• function n_hdlc_tty_receive
• function n_hdlc_tty_read
• function written
• function n_hdlc_tty_ioctl
• function scoped_guard
• function operations
• function n_hdlc_alloc_buf
• function n_hdlc_buf_return
• function n_hdlc_buf_put
• function n_hdlc_init
• function n_hdlc_exit
• module init n_hdlc_init

Annotated Snippet

module_init(n_hdlc_init);
module_exit(n_hdlc_exit);

MODULE_DESCRIPTION("HDLC line discipline support");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul Fulghum paulkf@microgate.com");
module_param(maxframe, int, 0);
MODULE_ALIAS_LDISC(N_HDLC);

Annotation

• Immediate include surface: `linux/module.h`, `linux/init.h`, `linux/kernel.h`, `linux/sched.h`, `linux/types.h`, `linux/fcntl.h`, `linux/interrupt.h`, `linux/ptrace.h`.
• Detected declarations: `struct n_hdlc_buf`, `struct n_hdlc_buf_list`, `struct n_hdlc`, `function flush_rx_queue`, `function flush_tx_queue`, `function n_hdlc_free_buf_list`, `function n_hdlc_tty_close`, `function n_hdlc_tty_open`, `function frame`, `function n_hdlc_tty_write_work`.
• Atlas domain: Driver Families / drivers/tty.
• Implementation status: integration implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.