wifi: iwlwifi: mvm/mld: use average RSSI for beacons

When connected to an AP, the PHY will typically be tuned to
a higher bandwidth than the beacons are transmitted on, as
they are normally only transmitted on 20 MHz. This can mean
that another STA is simultaneously transmitting on another
channel of the higher bandwidth, and apparently this energy
may be taken into account by the PHY, resulting in elevated
energy readings.

To work around this, track the firmware's corrected beacon
energy data and replace the RSSI in beacons by that. The
replacement happens for all beacons received in the context
of the current MAC or link (depending on FW version), in
which case the filters will drop all else. For a scan, which
is only tuning to 20 MHz channels, the MAC/link ID will be
one that isn't found (the AUX ID 4), and no correction will
be done (nor is it needed.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250711183056.324bfe7027ff.I160f947e7aab30e0110a7019ed46186e57c3de14@changeid

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mld/link.c b/drivers/net/wireless/intel/iwlwifi/mld/link.c
index c65ac6ecbd1d..ff237f78a468 100644
--- a/drivers/net/wireless/intel/iwlwifi/mld/link.c
+++ b/drivers/net/wireless/intel/iwlwifi/mld/link.c
@@ -783,6 +783,7 @@ iwl_mld_init_link(struct iwl_mld *mld, struct ieee80211_bss_conf *link,
 {
 	mld_link->vif = link->vif;
 	mld_link->link_id = link->link_id;
+	mld_link->average_beacon_energy = 0;
 
 	iwl_mld_init_internal_sta(&mld_link->bcast_sta);
 	iwl_mld_init_internal_sta(&mld_link->mcast_sta);
@@ -1216,3 +1217,22 @@ unsigned int iwl_mld_get_link_grade(struct iwl_mld *mld,
 	return grade;
 }
 EXPORT_SYMBOL_IF_IWLWIFI_KUNIT(iwl_mld_get_link_grade);
+
+void iwl_mld_handle_beacon_filter_notif(struct iwl_mld *mld,
+					struct iwl_rx_packet *pkt)
+{
+	const struct iwl_beacon_filter_notif *notif = (const void *)pkt->data;
+	u32 link_id = le32_to_cpu(notif->link_id);
+	struct ieee80211_bss_conf *link_conf =
+		iwl_mld_fw_id_to_link_conf(mld, link_id);
+	struct iwl_mld_link *mld_link;
+
+	if (IWL_FW_CHECK(mld, !link_conf, "invalid link ID %d\n", link_id))
+		return;
+
+	mld_link = iwl_mld_link_from_mac80211(link_conf);
+	if (WARN_ON_ONCE(!mld_link))
+		return;
+
+	mld_link->average_beacon_energy = le32_to_cpu(notif->average_energy);
+}