linux-drivers/
drivers/char/ipmi

IPMI host and BMC interfaces (KCS, SMIC, BT, SSIF, IPMB)

Kernel support for the Intelligent Platform Management Interface, the long-standing protocol servers use for out-of-band management like power control, sensor monitoring, and watchdog timers. It covers both the host side talking to a BMC over KCS, SMIC, BT, SSIF, or IPMB, and the BMC side on ASPEED and Nuvoton management SoCs.

keep conf=0.87 deploy=medium replacement=none subsystem=char category=infrastructure
87%

recommendation

It should stay because IPMI remains the standard out-of-band management protocol on servers, and the subsystem is still receiving active maintenance with bug fixes landing in 2026. While Redfish is gradually displacing IPMI for new deployments, BMC silicon vendors such as ASPEED still ship new chips (AST2700) and major server vendors like HPE continue to expose IPMI 2.0 on current iLO generations, so a large installed base depends on it.

repository signals

38 files
21,786 source lines
192 commits, 5y
+5,730 / −2,714 lines added / removed, 5y
65 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 192 total · active in 50/61 months
2021 2022 2023 2024 2025 2026 2021-04: 0 commits · +0 −0 2021-05: 1 commit · +12 −10 2021-06: 15 commits · +1,890 −1,073 2021-07: 3 commits · +12 −12 2021-08: 1 commit · +7 −9 2021-09: 10 commits · +833 −103 2021-10: 5 commits · +53 −24 2021-11: 6 commits · +35 −10 2021-12: 5 commits · +18 −12 2022-01: 0 commits · +0 −0 2022-02: 4 commits · +59 −70 2022-03: 6 commits · +93 −9 2022-04: 10 commits · +68 −51 2022-05: 1 commit · +1 −0 2022-06: 0 commits · +0 −0 2022-07: 2 commits · +4 −4 2022-08: 2 commits · +25 −13 2022-09: 5 commits · +34 −29 2022-10: 6 commits · +922 −17 2022-11: 4 commits · +7 −4 2022-12: 2 commits · +1 −8 2023-01: 4 commits · +57 −60 2023-02: 2 commits · +3 −2 2023-03: 3 commits · +3 −17 2023-04: 2 commits · +5 −3 2023-05: 2 commits · +5 −5 2023-06: 6 commits · +28 −17 2023-07: 1 commit · +0 −1 2023-08: 1 commit · +1 −1 2023-09: 1 commit · +4 −9 2023-10: 1 commit · +0 −1 2023-11: 2 commits · +5 −9 2023-12: 1 commit · +2 −2 2024-01: 0 commits · +0 −0 2024-02: 0 commits · +0 −0 2024-03: 7 commits · +26 −37 2024-04: 1 commit · +9 −8 2024-05: 0 commits · +0 −0 2024-06: 1 commit · +4 −2 2024-07: 1 commit · +7 −7 2024-08: 2 commits · +24 −1 2024-09: 3 commits · +4 −2 2024-10: 0 commits · +0 −0 2024-11: 1 commit · +1 −1 2024-12: 3 commits · +12 −22 2025-01: 2 commits · +4 −3 2025-02: 0 commits · +0 −0 2025-03: 16 commits · +401 −401 2025-04: 7 commits · +217 −166 2025-05: 2 commits · +12 −7 2025-06: 1 commit · +42 −17 2025-07: 2 commits · +4 −8 2025-08: 11 commits · +184 −116 2025-09: 5 commits · +425 −227 2025-10: 1 commit · +4 −1 2025-11: 1 commit · +3 −6 2025-12: 0 commits · +0 −0 2026-01: 4 commits · +39 −21 2026-02: 7 commits · +121 −76 2026-03: 0 commits · +0 −0 2026-04: 0 commits · +0 −0

sources

  1. lore.kernel.org

    Recent upstream maintenance in 2026 on ipmi_msghandler.c shows the subsystem is still actively fixed.

  2. lore.kernel.org

    Another 2026 bug-fix patch against ipmi_msghandler.c indicates ongoing bug-fix traffic rather than abandonment.

  3. aspeedtech.com

    ASPEED's current server-management lineup still markets new BMC SoCs (including AST2700 series), showing BMC hardware remains actively sold.

  4. support.hpe.com

    HPE iLO 7 documentation states current server management still provides IPMI 2.0 capabilities, indicating ongoing deployment on modern servers.

codex reasoning notes (technical)

Recommendation is keep: provided static history already shows 182 substantive commits in 5y, 54 authors, and a most recent substantive touch on 2026-02-23. I confirmed recent upstream attention with lore_activity on drivers/char/ipmi/ipmi_msghandler.c, which returned 2026 fixes at the cited lore URLs. I checked removal/deprecation talk with lore_regex twice, but both subject scans timed out; no positive removal evidence was obtained. A local shell read of drivers/char/ipmi/Kconfig shows this directory still covers active host-side and BMC-side interfaces (IPMI_SI, SSIF, IPMB, watchdog/poweroff, ASPEED KCS/BT BMC, NPCM7xx KCS, SSIF BMC), so there is no single upstream replacement driver. Deployment is medium, not high, because Redfish increasingly displaces IPMI for new management workflows, but official web.search_query results show both current BMC silicon sales (ASPEED server-management pages) and ongoing modern-server IPMI exposure (HPE iLO 7 docs).