linux-drivers/
drivers/tty/serial/8250

8250/16550-compatible UART serial ports

The generic Linux support for 8250- and 16550-family serial UARTs, the long-standing standard for RS-232-style serial ports. It covers traditional PC COM ports, server baseboard management console serial links, industrial PCIe multi-port serial cards, USB-attached UARTs, and the debug/console serial lines on countless embedded boards from the 1980s through hardware still being sold today.

keep conf=0.96 deploy=high replacement=none subsystem=tty category=other
96%

recommendation

It should stay because 8250/16550-compatible UARTs are still everywhere in 2025: PC serial ports, server BMC consoles, industrial PCIe multi-port serial cards, and the debug consoles on virtually every embedded Linux board. Upstream activity is healthy, with frequent fixes and new device IDs landing as recently as this year, including support for Microchip's PCI1xxxx PCIe serial controllers. There is no replacement; this directory is the umbrella implementation for the entire UART class.

repository signals

52 files
28,476 source lines
641 commits, 5y
+12,369 / −6,906 lines added / removed, 5y
152 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 641 total · active in 59/61 months
2021 2022 2023 2024 2025 2026 2021-04: 6 commits · +30 −33 2021-05: 13 commits · +122 −70 2021-06: 12 commits · +198 −94 2021-07: 12 commits · +89 −27 2021-08: 1 commit · +2 −4 2021-09: 7 commits · +30 −15 2021-10: 14 commits · +110 −135 2021-11: 8 commits · +260 −425 2021-12: 7 commits · +112 −53 2022-01: 5 commits · +129 −84 2022-02: 13 commits · +133 −73 2022-03: 9 commits · +136 −41 2022-04: 25 commits · +728 −305 2022-05: 10 commits · +50 −67 2022-06: 44 commits · +342 −232 2022-07: 10 commits · +158 −34 2022-08: 5 commits · +27 −31 2022-09: 9 commits · +47 −32 2022-10: 12 commits · +146 −36 2022-11: 14 commits · +71 −37 2022-12: 0 commits · +0 −0 2023-01: 4 commits · +211 −4 2023-02: 15 commits · +679 −58 2023-03: 4 commits · +39 −10 2023-04: 8 commits · +34 −2 2023-05: 22 commits · +478 −244 2023-06: 4 commits · +35 −77 2023-07: 10 commits · +187 −79 2023-08: 10 commits · +26 −14 2023-09: 25 commits · +248 −277 2023-10: 21 commits · +547 −171 2023-11: 5 commits · +50 −78 2023-12: 9 commits · +262 −56 2024-01: 7 commits · +154 −18 2024-02: 14 commits · +116 −103 2024-03: 18 commits · +206 −367 2024-04: 20 commits · +1,225 −262 2024-05: 19 commits · +769 −770 2024-06: 7 commits · +47 −19 2024-07: 5 commits · +135 −25 2024-08: 18 commits · +102 −104 2024-09: 3 commits · +13 −10 2024-10: 8 commits · +151 −131 2024-11: 2 commits · +14 −2 2024-12: 10 commits · +128 −63 2025-01: 12 commits · +419 −266 2025-02: 8 commits · +73 −162 2025-03: 14 commits · +608 −111 2025-04: 6 commits · +39 −18 2025-05: 2 commits · +14 −18 2025-06: 32 commits · +918 −768 2025-07: 7 commits · +38 −37 2025-08: 10 commits · +278 −367 2025-09: 4 commits · +70 −16 2025-10: 4 commits · +546 −2 2025-11: 11 commits · +94 −119 2025-12: 4 commits · +23 −16 2026-01: 8 commits · +113 −121 2026-02: 13 commits · +342 −113 2026-03: 1 commit · +17 −0 2026-04: 0 commits · +0 −0

sources

  1. git.kernel.org

    Upstream activity is current and substantial; the directory is still seeing frequent fixes and new-device enablement rather than retirement.

  2. cateee.net

    The directory is the generic in-tree driver family for 8250/16550-compatible serial hardware and remains present through current kernel releases.

  3. cateee.net

    Newer hardware support exists inside this directory, including Microchip PCI1xxxx-based serial ports added in recent kernels.

  4. ww1.microchip.com

    Microchip's recent PCI1xxxx documentation describes UART-capable PCIe devices, indicating this class of 8250-backed hardware is still an actively marketed platform.

  5. developerhelp.microchip.com

    Current embedded Linux development boards still rely on UART console deployments, showing ongoing real-world use of this driver class.

codex reasoning notes (technical)

Keep. This is the generic serial/UART core plus many active subdrivers, not an obsolete niche leaf. Local shell inspection (`rg --files`, `git -c safe.directory=... log`) showed broad file coverage and many 2025-2026 fixes/new IDs, with no sign of decay. `git.kernel.org` log URL is canonical recall used to anchor upstream activity; LKDDb and Microchip URLs were obtained via web search. Web search for lore removal/deprecation discussion produced no useful results, so there is no evidence of an active removal series. Because 8250/16550-compatible UARTs remain common in PCs, server BMCs, industrial PCIe serial cards, and embedded debug consoles, deployments are still high. No single replacement driver exists; this directory is itself the umbrella implementation for the use case.