STRUCT CDX_MCDI_IFACE(9)

🦋 struct cdx_mcdi_iface(9) — the MCDI protocol context, explained

okay so bestie, welcome to the Kernel API Manual page for struct cdx_mcdi_iface ✨ this is the little home where the MCDI protocol context lives, and honestly? it's giving main character energy in the CDX world 💅

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🌸 NAME

struct cdx_mcdi_iface — the MCDI protocol context 🎀

like, this struct is the vibe where all your MCDI state hangs out. periodt.

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✨ SYNOPSIS

struct cdx_mcdi_iface {
    struct cdx_mcdi *cdx;
    struct mutex iface_lock;
    unsigned int outstanding_cleanups;
    struct list_head cmd_list;
    struct workqueue_struct *workqueue;
    wait_queue_head_t cmd_complete_wq;
    struct cdx_mcdi_cmd *db_held_by;
    struct cdx_mcdi_cmd *seq_held_by[16];
    unsigned int prev_handle;
    enum cdx_mcdi_mode mode;
    u8 prev_seq;
    bool new_epoch;
 };

no cap, that's the whole shape of it 💖

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🫶 Members (the whole cast, no one gets left out)

• cdx — the associated NIC 💻 like, the network interface this whole thing is attached to.
• iface_lock — serialise access to this structure 🔒 literally the bouncer at the door, one at a time please.
• outstanding_cleanups — count of cleanups 🧹 keeping track of how many cleanups are still outstanding.
• cmd_list — list of outstanding and running commands 📋 both the ones in flight and the ones still waiting, all in one list.
• workqueue — workqueue used for delayed processing ⏳ the place where delayed work gets handled.
• cmd_complete_wq — waitqueue for command completion 😴 you sit here and wait until your command is done.
• db_held_by — the command the MC doorbell is in use by 🔔 whoever's holding the doorbell right now.
• seq_held_by — the command each sequence number is in use by 🔢 an array where each slot says which command is using that sequence number.
• prev_handle — the last used command handle 🏷️ the handle that got used most recently.
• mode — poll for mcdi completion, or wait for an mcdi_event 👀 two whole lifestyles: you either poll, or you wait for the event. choose your fighter.
• prev_seq — the last used sequence number 🔁 same energy as prev_handle, but for sequences.
• new_epoch — indicates start of day or start of MC reboot recovery 🌅 a fresh start — either the beginning of a day or the beginning of MC reboot recovery. iconic either way.

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👑 SEE ALSO

• Kernel file ./include/linux/cdx/mcdi.h
• enum cdx_mcdi_mode(9)
• enum cdx_mcdi_cmd_state(9)
• struct cdx_mcdi(9)
• struct cdx_mcdi_cmd(9)
• struct cdx_mcdi_data(9)

go read those next, bestie, iykyk 🧚

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heads up glampire: this page is filed under ./include/linux/cdx and it's dated October 2026 — that's the source and the version/date, so don't @ me when you're citing it 💅

and that's the whole page — struct cdx_mcdi_iface(9) from the Kernel API Manual, source ./include/linux/cdx, October 2026. slay 🎀⭐🔥