Ownership(9)

💅 Ownership 💅

okay bestie, so this page is Ownership(9) out of the Kernel API Manual, and it's honestly giving "two parents fighting over custody of the wifi card" 😭

The device can be controlled either by the CSME firmware or by the host driver: iwlwifi. There's a whole negotiation between those two entities to figure out who controls (or, like, owns) the device. 🫶

And here's the part that matters: since the CSME can control the device even when the OS is not working or even, like, completely missing, the CSME can straight-up request the device if it comes to the conclusion that the OS's host driver is not operational. iconic but also kind of threatening 💀

Which is exactly why the host driver needs to signal CSME that it is up and running. fr fr, it's a check-in text. "hi bestie I'm alive" ✨

And if the driver is unloaded? It'll signal CSME that it is going down, so that CSME can take ownership. very much "k bye handing you the aux cord" energy 🎀

lowkey important: the ownership handoff is the whole vibe here — nobody controls the device without the other one knowing. no cap. 🔥

✨ SEE ALSO ✨

the reading list, and yes, we're reading all of it 👑

• kernel file ./drivers/net/wireless/intel/iwlwifi/mei/sap.h
• Introduction(9)
• Initial Handshake(9)
• Host and driver state messages(9)
• Ownership transfer(9)
• Data messages(9)
• enum iwl_sap_me_msg_id(9)
• struct iwl_sap_me_msg_hdr(9)
• struct iwl_sap_me_msg_start(9)
• struct iwl_sap_me_msg_start_ok(9)
• enum iwl_sap_msg(9)
• struct iwl_sap_hdr(9)
• struct iwl_sap_msg_dw(9)
• enum iwl_sap_nic_owner(9)
• enum iwl_sap_wifi_cipher_alg(9)
• struct iwl_sap_notif_connection_info(9)
• enum iwl_sap_scan_request(9)
• struct iwl_sap_notif_conn_status(9)
• enum iwl_sap_radio_state_bitmap(9)
• enum iwl_sap_notif_host_suspends_bitmap(9)
• struct iwl_sap_notif_country_code(9)
• struct iwl_sap_notif_host_link_up(9)
• enum iwl_sap_notif_link_down_type(9)
• struct iwl_sap_notif_host_link_down(9)
• struct iwl_sap_notif_host_nic_info(9)
• struct iwl_sap_notif_dw(9)
• struct iwl_sap_notif_sar_limits(9)
• enum iwl_sap_nvm_caps(9)
• struct iwl_sap_nvm(9)
• enum iwl_sap_eth_filter_flags(9)
• struct iwl_sap_eth_filter(9)
• enum iwl_sap_flex_filter_flags(9)
• struct iwl_sap_flex_filter(9)
• enum iwl_sap_ipv4_filter_flags(9)
• struct iwl_sap_ipv4_filter(9)
• enum iwl_sap_ipv6_filter_flags(9)
• struct iwl_sap_ipv6_filter(9)
• enum iwl_sap_icmpv6_filter_flags(9)
• enum iwl_sap_vlan_filter_flags(9)
• struct iwl_sap_oob_filters(9)
• struct iwl_sap_csme_filters(9)
• struct iwl_sap_cb_data(9)
• struct iwl_sap_pldr_data(9)
• enum iwl_sap_pldr_status(9)

and that's the whole page, bestie 🦋 k-thanks-bye from ./drivers/net/wireless/intel/i..., dated October 2026 — signed, sealed, delivered, Ownership(9) 💜✨