MDIO bus controllers and multiplexers for Ethernet PHYs
Low-level controller and multiplexer drivers for the MDIO bus, the small management channel CPUs and SoCs use to configure Ethernet PHY chips. They cover MDIO hardware on embedded SoCs, server baseboard management controllers like ASPEED's AST2600, and PCI networking silicon, with new entries still being added for parts shipping in 2025 and 2026.
recommendation
It should stay in the kernel because the directory is actively maintained and still gaining new drivers. A brand-new controller for Microchip's PIC64-HPSC family was added in early 2026, and the ASPEED AST2600 BMC controller (still sold for current servers) received stable backports the same month, showing the subtree is essential for both new silicon and shipping platforms.
repository signals
sources
- lore.kernel.org
Netdev patch series in April 2026 adds a new PIC64-HPSC/HX MDIO controller driver under drivers/net/mdio, showing ongoing upstream enablement for new hardware.
- lore.kernel.org
A January 2026 stable backport fixes drivers/net/mdio/mdio-aspeed.c, showing the directory is still receiving maintained bug-fix traffic.
- microchip.com
Microchip markets the PIC64-HPSC family as a current product line with Linux support and evaluation hardware, indicating new deployments rather than legacy-only use.
- aspeedtech.com
ASPEED still lists the AST2600 server-management SoC as a current product, supporting continued relevance of MDIO controller drivers for shipping BMC/server platforms.
codex reasoning notes (technical)
Real driver directory, not a helper-only subtree: it contains many module_platform_driver/module_pci_driver MDIO controller and mux drivers. Lore evidence was obtained via mcp__lore_http__.lore_file_timeline on drivers/net/mdio/mdio-pic64hpsc.c and drivers/net/mdio/mdio-aspeed.c; these show a brand-new 2026 driver addition plus 2026 stable fixes, with no sign here of abandonment. Product-status evidence was obtained via web search on Microchip and ASPEED vendor pages. Because the subtree is actively extended for new silicon and still used in current embedded/BMC/networking SoCs, there is no natural replacement beyond keeping the per-controller drivers.