STRUCT DRM_DP_MST_TOPOLOGY_STATE(9)

✨ struct drm_dp_mst_topology_state — DisplayPort MST topology atomic state ✨

okay so bestie, we're in the Kernel API Manual and this page is literally all about struct drm_dp_mst_topology_state, the DisplayPort MST topology atomic state. buckle up 💖

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🌸 NAME 🌸

struct drm_dp_mst_topology_state — DisplayPort MST topology atomic state, no cap 🫶

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🦋 SYNOPSIS 🦋

here's the struct in all its glory, copy it exactly bestie:

struct drm_dp_mst_topology_state {
    struct drm_private_state base;
    struct drm_dp_mst_topology_mgr *mgr;
    u32 pending_crtc_mask;
    struct drm_crtc_commit **commit_deps;
    size_t num_commit_deps;
    u32 payload_mask;
    struct list_head payloads;
    u8 total_avail_slots;
    u8 start_slot;
    fixed20_12 pbn_div;
 };

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💅 MEMBERS 💅

every field, one by one, we're not skipping a single one 👑

• base — the base private state for atomic. it's giving foundation, it's giving main character energy 🌟
• mgr — the topology manager. the boss of this whole situation 🔥
• pending_crtc_mask — a bitmask of all the CRTCs this topology state touches. drivers are allowed to modify this to add extra dependencies if they need to, so like… go off, add your deps 💫
• commit_deps — a list of all the CRTC commits affecting this topology. lowkey important caveat: this field isn't populated until drm_dp_mst_atomic_wait_for_dependencies gets called. so don't come for it before then, it's not ready 😭
• num_commit_deps — the number of CRTC commits in commit_deps. the headcount, the attendance list 🎀
• payload_mask — a bitmask of allocated VCPIs, used for VCPI assignments ✨
• payloads — the list of payloads being created/destroyed in this state. it's giving construction site and demolition at the same time ��
• total_avail_slots — the total number of slots this topology can handle. and it's 63 or 64, exactly those, don't @ me 🍓
• start_slot — the first usable time slot in this topology, and that's 1 or 0 🌈
• pbn_div — the current PBN divisor for this topology. key detail bestie: the driver is expected to fill this out itself, so it's not doing it for you 💀

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🧚 DESCRIPTION 🧚

so like, this struct represents the atomic state of the toplevel DisplayPort MST manager. that's the whole vibe. iconic, honestly ✨

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👑 SEE ALSO 👑

go read these next, they're all linked and they all slay:

• Kernel file ./include/drm/display/drm_dp_mst_helper.h
• struct drm_dp_mst_port(9)
• struct drm_dp_mst_branch(9)
• struct drm_dp_mst_atomic_payload(9)
• struct drm_dp_mst_topology_mgr(9)
• enum drm_dp_mst_mode(9)
• __drm_dp_mst_state_iter_get(9)
• for_each_oldnew_mst_mgr_in_state(9)
• for_each_old_mst_mgr_in_state(9)
• for_each_new_mst_mgr_in_state(9)

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and that's the page, bestie 🫶 this one came from ./include/drm/display, dated October 2026, and the whole thing is filed under struct drm_d...pology_state(9) in the Kernel API Manual. drink some water, go read your headers, mwah 💖🎀