mac80211: Fix station bandwidth setting after channel switch

When performing a channel switch flow for a managed interface, the
flow did not update the bandwidth of the AP station and the rate
scale algorithm. In case of a channel width downgrade, this would
result with the rate scale algorithm using a bandwidth that does not
match the interface channel configuration.

Fix this by updating the AP station bandwidth and rate scaling algorithm
before the actual channel change in case of a bandwidth downgrade, or
after the actual channel change in case of a bandwidth upgrade.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index a59187c016e08193e50078becbd169820f2efe9a..22b6994601765cf4135b7a2115d02e4eefb5d750 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -978,6 +978,10 @@ static void ieee80211_chswitch_work(struct work_struct *work)
         */
 
        if (sdata->reserved_chanctx) {
+               struct ieee80211_supported_band *sband = NULL;
+               struct sta_info *mgd_sta = NULL;
+               enum ieee80211_sta_rx_bandwidth bw = IEEE80211_STA_RX_BW_20;
+
                /*
                 * with multi-vif csa driver may call ieee80211_csa_finish()
                 * many times while waiting for other interfaces to use their
@@ -986,6 +990,48 @@ static void ieee80211_chswitch_work(struct work_struct *work)
                if (sdata->reserved_ready)
                        goto out;
 
+               if (sdata->vif.bss_conf.chandef.width !=
+                   sdata->csa_chandef.width) {
+                       /*
+                        * For managed interface, we need to also update the AP
+                        * station bandwidth and align the rate scale algorithm
+                        * on the bandwidth change. Here we only consider the
+                        * bandwidth of the new channel definition (as channel
+                        * switch flow does not have the full HT/VHT/HE
+                        * information), assuming that if additional changes are
+                        * required they would be done as part of the processing
+                        * of the next beacon from the AP.
+                        */
+                       switch (sdata->csa_chandef.width) {
+                       case NL80211_CHAN_WIDTH_20_NOHT:
+                       case NL80211_CHAN_WIDTH_20:
+                       default:
+                               bw = IEEE80211_STA_RX_BW_20;
+                               break;
+                       case NL80211_CHAN_WIDTH_40:
+                               bw = IEEE80211_STA_RX_BW_40;
+                               break;
+                       case NL80211_CHAN_WIDTH_80:
+                               bw = IEEE80211_STA_RX_BW_80;
+                               break;
+                       case NL80211_CHAN_WIDTH_80P80:
+                       case NL80211_CHAN_WIDTH_160:
+                               bw = IEEE80211_STA_RX_BW_160;
+                               break;
+                       }
+
+                       mgd_sta = sta_info_get(sdata, ifmgd->bssid);
+                       sband =
+                               local->hw.wiphy->bands[sdata->csa_chandef.chan->band];
+               }
+
+               if (sdata->vif.bss_conf.chandef.width >
+                   sdata->csa_chandef.width) {
+                       mgd_sta->sta.bandwidth = bw;
+                       rate_control_rate_update(local, sband, mgd_sta,
+                                                IEEE80211_RC_BW_CHANGED);
+               }
+
                ret = ieee80211_vif_use_reserved_context(sdata);
                if (ret) {
                        sdata_info(sdata,
@@ -996,6 +1042,13 @@ static void ieee80211_chswitch_work(struct work_struct *work)
                        goto out;
                }
 
+               if (sdata->vif.bss_conf.chandef.width <
+                   sdata->csa_chandef.width) {
+                       mgd_sta->sta.bandwidth = bw;
+                       rate_control_rate_update(local, sband, mgd_sta,
+                                                IEEE80211_RC_BW_CHANGED);
+               }
+
                goto out;
        }