cfg80211_inc...ignal_notify(9)

📦 version 7.3.1, in nixpkgs unstable

💖 cfg80211_incumbent_signal_notify 💖

okay so bestie, welcome to the Kernel API Manual ✨ — today's main character is cfg80211_incumbent_signal_notify, and she is literally the one who tells userspace "hey girl, we detected an incumbent signal 👀". no cap, she's important. let's get into it 🫶

✨ NAME ✨

cfg80211_incumbent_signal_notify — Notify userspace of incumbent signal detection 💅

🌸 SYNOPSIS 🌸

void cfg80211_incumbent_signal_notify(struct wiphy *wiphy,
                                      const struct cfg80211_chan_def *chandef,
                                      u32 signal_interference_bitmap,
                                      gfp_t gfp);

🎀 ARGUMENTS 🎀

  • wiphy — the wiphy to use 🌈 (yes, THE wiphy, the whole vibe)
  • chandef — channel definition in which the interference was detected 👑
  • signal_interference_bitmap — bitmap indicating interference across 20 MHz segments 🦋
  • gfp — allocation context for message creation and multicast 🔥. pass GFP_ATOMIC if called from atomic context (e.g. firmware event handler), otherwise GFP_KERNEL. choose wisely bestie, this one matters 💀

🧚 DESCRIPTION 🧚

Use this function to notify userspace when an incumbent signal is detected on the operating channel in the 6 GHz band ✨. fr fr, that's her whole job.

The notification includes the current channel definition and a bitmap representing interference across the operating bandwidth 📶. Each bit in the bitmap corresponds to a 20 MHz segment, with the lowest bit representing the lowest frequency segment 💜.

And listen — punctured sub-channels are included in the bitmap structure but are always set to zero 🙈, since interference detection is not performed on them. so they're invited to the party but they're not doing anything, iykyk 💅

✨ SEE ALSO ✨

okay so the SEE ALSO section is lowkey the whole extended universe, bestie. it's giving extended cinematic universe 💅. every single cross-reference is here, fr fr — no skips, no summaries, no "you'll figure it out."

then we slide into actions + config, aka the "i can fix her" zone:

scanning + BSS list handling next, because of course she has a whole scanning arc:

  • Scanning and BSS list handling(9), struct cfg80211_ssid(9), struct cfg80211_scan_info(9), struct cfg80211_scan_6ghz_params(9), struct cfg80211_scan_request(9), struct cfg80211_match_set(9), struct cfg80211_sched_scan_plan(9), struct cfg80211_bss_select_adjust(9), struct cfg80211_sched_scan_request(9).
  • enum cfg80211_signal_type(9), struct cfg80211_inform_bss(9), struct cfg80211_bss_ies(9), struct cfg80211_bss(9), ieee80211_bss_get_elem(9), ieee80211_bss_get_ie(9), struct cfg80211_auth_request(9), struct cfg80211_assoc_link(9), struct cfg80211_ml_reconf_req(9).
  • enum cfg80211_assoc_req_flags(9), struct cfg80211_assoc_request(9), struct cfg80211_deauth_request(9), struct cfg80211_disassoc_request(9), struct cfg80211_ibss_params(9), struct cfg80211_bss_selection(9), struct cfg80211_connect_params(9), enum cfg80211_connect_params_changed(9).
  • enum wiphy_params_flags(9), struct cfg80211_pmksa(9), struct cfg80211_pkt_pattern(9), struct cfg80211_wowlan_tcp(9), struct cfg80211_wowlan(9), struct cfg80211_coalesce_rules(9), struct cfg80211_coalesce(9), struct cfg80211_wowlan_nd_match(9), struct cfg80211_wowlan_nd_info(9), struct cfg80211_wowlan_wakeup(9).
  • struct cfg80211_gtk_rekey_data(9), struct cfg80211_update_ft_ies_params(9), struct cfg80211_mgmt_tx_params(9), struct cfg80211_dscp_exception(9), struct cfg80211_dscp_range(9), struct cfg80211_qos_map(9).
  • Neighbor Awareness Networking (NAN)(9), struct cfg80211_nan_band_config(9), struct cfg80211_nan_conf(9), struct cfg80211_nan_channel(9), struct cfg80211_nan_local_sched(9), struct cfg80211_nan_peer_map(9), struct cfg80211_nan_peer_sched(9), enum cfg80211_nan_conf_changes(9), struct cfg80211_nan_func_filter(9), struct cfg80211_nan_func(9).
  • struct cfg80211_pmk_conf(9), struct cfg80211_external_auth_params(9), struct cfg80211_ftm_responder_stats(9), struct cfg80211_pmsr_ftm_result(9), struct cfg80211_pmsr_result(9), struct cfg80211_pmsr_ftm_request_peer(9), struct cfg80211_pmsr_request_peer(9), struct cfg80211_pmsr_request(9), struct cfg80211_update_owe_info(9), struct mgmt_frame_regs(9).

then the wiphy / ops / lifecycle besties — highkey the main characters:

utility functions + data path helpers, aka the "little helpers that could":

regulatory + notification + rfkill + vendor + test mode + connect/disconnect + mgmt + CQM + radar + everything else — literally the rest of the group chat:

okay so here's the entire cross-reference squad — and bestie, it is LONG 😭 so I grouped them into little clusters so your brain doesn't fully melt. Every single one is a real page you can go read, fr fr, no cap 💖

🌸 regulatory + beacon girlies

  • cfg80211_reg_check_beaconing — the beaconing check one.
  • cfg80211_reg_can_beacon — can we beacon? asking for a friend.
  • cfg80211_reg_can_beacon_relax — same question, but relaxed 💅

🦋 channel switch + chandef math

  • cfg80211_ch_switch_notify — channel switch, but make it a notification.
  • cfg80211_ch_switch_started_notify — and this is the "we started" version of it.
  • ieee80211_operating_class_to_band — operating class ➡️ band.
  • ieee80211_operating_class_to_chandef — operating class ➡️ chandef.
  • ieee80211_chandef_to_operating_class — chandef ➡️ operating class (the reverse, she's versatile).
  • ieee80211_chandef_to_khz — chandef ➡️ kHz, numbers era.
  • cfg80211_tdls_oper_request — the TDLS oper request one.
  • cfg80211_calculate_bitrate — math time, bitrate edition.
  • cfg80211_unregister_wdev — unregistering a wdev.
  • cfg80211_register_netdevice — registering a netdevice ✨
  • cfg80211_unregister_netdevice — and taking it back out again.
  • cfg80211_stop_link — stop that link.
  • cfg80211_stop_iface — stop that interface.
  • cfg80211_shutdown_all_interfaces — all of them. every last one. 💀
  • cfg80211_iftype_allowed — is this iftype allowed or not.
  • cfg80211_links_removed — links got removed, noting it.

🧚 fast transition, P2P + IE parsing

  • struct cfg80211_ft_event_params — the struct, not the function, keep up bestie.
  • cfg80211_ft_event — the FT event itself.
  • cfg80211_get_p2p_attr — grabbing a P2P attribute.
  • ieee80211_ie_split_ric — IE splitting, RIC flavour.
  • ieee80211_ie_split — IE splitting, classic flavour.
  • ieee80211_fragment_element — fragmenting an element 🫶

🌈 power save, wowlan + crit proto

  • cfg80211_report_wowlan_wakeup — reporting a WoWLAN wakeup, sleepy girl behaviour.
  • cfg80211_crit_proto_stopped — the critical protocol stopped, noted.
  • ieee80211_get_num_supported_channels — how many channels are supported, count 'em.

⭐ combinations + channel bookkeeping

  • cfg80211_check_combinations — checking combinations.
  • cfg80211_iter_combinations — iterating combinations (she loops, she slays).
  • cfg80211_get_radio_idx_by_chan — radio index, by channel.
  • cfg80211_schedule_channels_check — schedule that channels check 📅

💜 wiphy features + debugfs

  • wiphy_ext_feature_set — set an extended feature flag.
  • wiphy_ext_feature_isset — is it set? asking.
  • wiphy_locked_debugfs_read — debugfs read, locked edition.
  • wiphy_locked_debugfs_write — debugfs write, locked edition.

🍓 NAN crew (there are SO many of them)

  • cfg80211_free_nan_func — free the NAN function.
  • struct cfg80211_nan_match_params — a struct this time, iconic.
  • cfg80211_nan_match — NAN match.
  • cfg80211_nan_func_terminated — the NAN function terminated.
  • cfg80211_nan_sched_update_done — NAN schedule update, done.
  • cfg80211_next_nan_dw_notif — next NAN DW notification.
  • cfg80211_nan_cluster_joined — joined a NAN cluster 🫶
  • cfg80211_nan_ulw_update — NAN ULW update.
  • cfg80211_nan_channel_evac — NAN channel evac, everybody out.

🔥 auth, PMSR + assoc

  • cfg80211_external_auth_request — external auth request.
  • cfg80211_pmsr_report — PMSR report.
  • cfg80211_pmsr_complete — PMSR complete, we're done here.
  • cfg80211_assoc_comeback — the assoc comeback, she returned.
  • cfg80211_update_owe_info_event — updating the OWE info event.

👑 BSS + colour change saga

  • cfg80211_bss_flush — flush the BSS.
  • cfg80211_bss_color_notify — BSS color notification.
  • cfg80211_obss_color_collision_notify — OBSS color collision notification 🚨
  • cfg80211_color_change_started_notify — colour change started.
  • cfg80211_color_change_aborted_notify — colour change aborted 😭
  • cfg80211_color_change_notify — colour change, the notification.

🦋 6 GHz, EPCOS + MLO reconfig

  • cfg80211_6ghz_power_type — 6 GHz power type.
  • cfg80211_epcs_changed — EPCOS changed.
  • struct cfg80211_mlo_reconf_done_data — struct, MLO reconfig done data.
  • cfg80211_mlo_reconf_add_done — MLO reconfig add, done.

🌸 S1G odds and ends

  • cfg80211_s1g_get_start_freq_khz — S1G start frequency, in kHz.
  • cfg80211_s1g_get_end_freq_khz — S1G end frequency, in kHz.
  • cfg80211_s1g_get_primary_sibling — S1G primary sibling, the sibling in question 💅

and that's genuinely the whole squad — sixty-three of them, and yes I counted, and yes I need a nap 🫶 the source lives in ./include/net, dated October 2026, so go read the rest of the pages and hydrate while you're at it bestie 💖✨👑

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