STRUCT MDIO_IF_INFO(9)

✨ NAME ✨

Okay bestie, welcome to the Kernel API Manual 🫶 This page is all about struct mdio_if_info — the Ethernet controller MDIO interface. That’s the whole vibe: it’s the MDIO interface struct for an Ethernet controller, and we’re gonna go through every field like it’s a group chat screenshot. 💅

💅 SYNOPSIS 💅

Here’s the struct in all its exact, iconic glory — do not come for the commas, okay? 😭

       struct mdio_if_info {
           int prtad;
           u32 mmds;
           unsigned mode_support;
           struct net_device *dev;
           int (*mdio_read)(struct net_device *dev, int prtad, int devad, u16
       addr);
           int (*mdio_write)(struct net_device *dev, int prtad, int devad, u16
       addr, u16 val);
        };

🫶 Members 🫶

• prtad — PRTAD of the PHY (MDIO_PRTAD_NONE if not present/unknown). 🦋
• mmds — Mask of MMDs expected to be present in the PHY. This must be non-zero unless prtad = MDIO_PRTAD_NONE. ⚠️
• mode_support — MDIO modes supported. If MDIO_SUPPORTS_C22 is set then MII register access will be passed through with devad = MDIO_DEVAD_NONE. If MDIO_EMULATE_C22 is set then access to commonly used clause 22 registers will be translated into clause 45 registers. 💫
• dev — Net device structure. 🔌
• mdio_read — Register read function; returns value or negative error code. 📖
• mdio_write — Register write function; returns 0 or negative error code. ✍️

🔗 SEE ALSO 🔗

Kernel file ./include/linux/mdio.h is the spot, and these are the besties you should also go say hi to:

• mdio45_ethtool_ksettings_get(9)
• mmd_eee_cap_to_ethtool_sup_t(9)
• mmd_eee_adv_to_ethtool_adv_t(9)
• ethtool_adv_to_mmd_eee_adv_t(9)
• linkmode_adv_to_mii_10gbt_adv_t(9)
• mii_10gbt_stat_mod_linkmode_lpa_t(9)
• mii_t1_adv_l_mod_linkmode_t(9)
• mii_t1_adv_m_mod_linkmode_t(9)
• linkmode_adv_to_mii_t1_adv_l_t(9)
• linkmode_adv_to_mii_t1_adv_m_t(9)
• mii_eee_cap1_mod_linkmode_t(9)
• mii_eee_cap2_mod_linkmode_sup_t(9)
• mii_eee_cap2_mod_linkmode_adv_t(9)
• linkmode_to_mii_eee_cap1_t(9)
• linkmode_to_mii_eee_cap2_t(9)
• mii_10base_t1_adv_mod_linkmode_t(9)
• linkmode_adv_to_mii_10base_t1_t(9)
• mii_c73_mod_linkmode(9)
• mdio_module_driver(9)

xoxo, your Kernel API Manual bestie 💖 — source ./include/linux, dated October 2026, page struct mdio_if_info(9). Mwah 💋