wifi: iwlwifi: mld: add duplicated beacon RSSI adjustment

For 6 GHz duplicated beacons, the RSSI is measured only on the 20 MHz
primary channel while the actual beacon energy spans the full
operational bandwidth. This leads to underestimated link quality.

Detect duplicated beacons and apply bandwidth-based RSSI adjustments.

Signed-off-by: Avinash Bhatt <avinash.bhatt@intel.com>
Link: https://patch.msgid.link/20260512222731.a4c873e63054.Iea8e8a5f3b384622308dd8d03c5881ff75f1908c@changeid
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mld/link.c b/drivers/net/wireless/intel/iwlwifi/mld/link.c
index a8d146edc4bdb0410d4e8aec036fe8a83c62ed3f..c07a0d6b0bd422b7d6fa57ef9ccb653a8bc1f754 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mld/link.c
+++ b/drivers/net/wireless/intel/iwlwifi/mld/link.c
@@ -894,6 +894,60 @@ iwl_mld_get_avail_chan_load(struct iwl_mld *mld,
        return MAX_CHAN_LOAD - iwl_mld_get_chan_load(mld, link_conf);
 }
 
+static s8
+iwl_mld_get_dup_beacon_rssi_adjust(struct iwl_mld *mld,
+                                  struct ieee80211_bss_conf *link_conf)
+{
+       const struct ieee80211_he_6ghz_oper *he_6ghz_oper;
+       const struct cfg80211_bss_ies *beacon_ies;
+       const struct element *elem;
+
+       /* Duplicated beacon feature is only specific to 6 GHz */
+       if (WARN_ONCE(link_conf->chanreq.oper.chan->band != NL80211_BAND_6GHZ,
+                     "Unexpected band %d\n",
+                     link_conf->chanreq.oper.chan->band))
+               return 0;
+
+       lockdep_assert_wiphy(mld->wiphy);
+
+       beacon_ies = wiphy_dereference(mld->wiphy, link_conf->bss->beacon_ies);
+       if (!beacon_ies)
+               return 0;
+
+       elem = cfg80211_find_ext_elem(WLAN_EID_EXT_HE_OPERATION,
+                                     beacon_ies->data, beacon_ies->len);
+       if (!elem ||
+           elem->datalen < sizeof(struct ieee80211_he_operation) + 1 ||
+           elem->datalen < ieee80211_he_oper_size(&elem->data[1]))
+               return 0;
+
+       he_6ghz_oper = ieee80211_he_6ghz_oper((const void *)&elem->data[1]);
+       if (!he_6ghz_oper)
+               return 0;
+
+       if (!(he_6ghz_oper->control & IEEE80211_HE_6GHZ_OPER_CTRL_DUP_BEACON))
+               return 0;
+
+       /* Apply adjustment based on operational bandwidth */
+       switch (link_conf->chanreq.oper.width) {
+       case NL80211_CHAN_WIDTH_20:
+       case NL80211_CHAN_WIDTH_20_NOHT:
+               return 0;
+       case NL80211_CHAN_WIDTH_40:
+               return 3;
+       case NL80211_CHAN_WIDTH_80:
+               return 6;
+       case NL80211_CHAN_WIDTH_160:
+               return 9;
+       case NL80211_CHAN_WIDTH_320:
+               return 12;
+       default:
+               WARN_ONCE(1, "Unexpected channel width: %d\n",
+                         link_conf->chanreq.oper.width);
+               return 0;
+       }
+}
+
 /* This function calculates the grade of a link. Returns 0 in error case */
 unsigned int iwl_mld_get_link_grade(struct iwl_mld *mld,
                                    struct ieee80211_bss_conf *link_conf)
@@ -903,7 +957,7 @@ unsigned int iwl_mld_get_link_grade(struct iwl_mld *mld,
        s32 link_rssi;
        unsigned int grade = MAX_GRADE;
 
-       if (WARN_ON_ONCE(!link_conf))
+       if (WARN_ON_ONCE(!link_conf || !link_conf->bss))
                return 0;
 
        band = link_conf->chanreq.oper.chan->band;
@@ -918,8 +972,15 @@ unsigned int iwl_mld_get_link_grade(struct iwl_mld *mld,
         * For 6 GHz the RSSI of the beacons is lower than
         * the RSSI of the data.
         */
-       if (band == NL80211_BAND_6GHZ && link_rssi)
-               link_rssi += 4;
+       if (band == NL80211_BAND_6GHZ && link_rssi) {
+               s8 rssi_adj_6g =
+                       iwl_mld_get_dup_beacon_rssi_adjust(mld, link_conf);
+
+               if (!rssi_adj_6g)
+                       rssi_adj_6g = 4;
+
+               link_rssi += rssi_adj_6g;
+       }
 
        rssi_idx = band == NL80211_BAND_2GHZ ? 0 : 1;