mac80211: track AP's beacon rate and give it to the driver

Track the AP's beacon rate in the scan BSS data and in the
interface configuration to let the drivers know which rate
the AP is using. This information may be used by drivers,
in our case to let the firmware optimise beacon RX.

Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 17 insertions, 1 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 7a6f1a0207ec..a4dfb0be53d7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -94,6 +94,7 @@ struct ieee80211_bss {
 #define IEEE80211_MAX_SUPP_RATES 32
         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
         size_t supp_rates_len;
+        struct ieee80211_rate *beacon_rate;
 
         /*
          * During association, we save an ERP value from a probe response so
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ad9bb9e10cbb..87f2d4df31f8 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1779,8 +1779,10 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
                  * probably just won't work at all.
                  */
                 bss_conf->dtim_period = sdata->u.mgd.dtim_period ?: 1;
+                bss_conf->beacon_rate = bss->beacon_rate;
                 bss_info_changed |= BSS_CHANGED_BEACON_INFO;
         } else {
+                bss_conf->beacon_rate = NULL;
                 bss_conf->dtim_period = 0;
         }
 
@@ -1903,6 +1905,8 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
         del_timer_sync(&sdata->u.mgd.chswitch_timer);
 
         sdata->vif.bss_conf.dtim_period = 0;
+        sdata->vif.bss_conf.beacon_rate = NULL;
+
         ifmgd->have_beacon = false;
 
         ifmgd->flags = 0;
@@ -2754,8 +2758,10 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 
         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
                                         channel);
-        if (bss)
+        if (bss) {
                 ieee80211_rx_bss_put(local, bss);
+                sdata->vif.bss_conf.beacon_rate = bss->beacon_rate;
+        }
 
         if (!sdata->u.mgd.associated ||
             !ether_addr_equal(mgmt->bssid, sdata->u.mgd.associated->bssid))
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 99b103921a4b..1b122a79b0d8 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -140,6 +140,15 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
         }
 
+        if (beacon) {
+                struct ieee80211_supported_band *sband =
+                        local->hw.wiphy->bands[rx_status->band];
+                if (!(rx_status->flag & RX_FLAG_HT) &&
+                    !(rx_status->flag & RX_FLAG_VHT))
+                        bss->beacon_rate =
+                                &sband->bitrates[rx_status->rate_idx];
+        }
+
         return bss;
 }