mac80211: handle rate control (RC) racing with chanctx definition

chanctx represents the current phy configuration and rate scale uses
it for achieving max throughput, so if phy changes bandwidth to narrow
bandwidth, RC should be _first_ updated to avoid using the wider bandwidth
before updating the phy, and vice versa.

We assume in the patch that station interface is always updated before
updating phy context by calling ieee80211_vif_update_chandef.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.fc4e24496aa2.Ic40ea947c2f65739ea4b5fe3babd0a544240ced6@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 1 insertions, 88 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index b33b155f3573..97efc20b9825 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -371,7 +371,6 @@ static int ieee80211_config_bw(struct ieee80211_sub_if_data *sdata,
 	struct cfg80211_chan_def chandef;
 	u16 ht_opmode;
 	u32 flags;
-	enum ieee80211_sta_rx_bandwidth new_sta_bw;
 	u32 vht_cap_info = 0;
 	int ret;
 
@@ -450,35 +449,8 @@ static int ieee80211_config_bw(struct ieee80211_sub_if_data *sdata,
 		return -EINVAL;
 	}
 
-	switch (chandef.width) {
-	case NL80211_CHAN_WIDTH_20_NOHT:
-	case NL80211_CHAN_WIDTH_20:
-		new_sta_bw = IEEE80211_STA_RX_BW_20;
-		break;
-	case NL80211_CHAN_WIDTH_40:
-		new_sta_bw = IEEE80211_STA_RX_BW_40;
-		break;
-	case NL80211_CHAN_WIDTH_80:
-		new_sta_bw = IEEE80211_STA_RX_BW_80;
-		break;
-	case NL80211_CHAN_WIDTH_80P80:
-	case NL80211_CHAN_WIDTH_160:
-		new_sta_bw = IEEE80211_STA_RX_BW_160;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	if (new_sta_bw > sta->cur_max_bandwidth)
-		new_sta_bw = sta->cur_max_bandwidth;
-
-	if (new_sta_bw < sta->sta.bandwidth) {
-		sta->sta.bandwidth = new_sta_bw;
-		rate_control_rate_update(local, sband, sta,
-					 IEEE80211_RC_BW_CHANGED);
-	}
-
 	ret = ieee80211_vif_change_bandwidth(sdata, &chandef, changed);
+
 	if (ret) {
 		sdata_info(sdata,
 			   "AP %pM changed bandwidth to incompatible one - disconnect\n",
@@ -486,12 +458,6 @@ static int ieee80211_config_bw(struct ieee80211_sub_if_data *sdata,
 		return ret;
 	}
 
-	if (new_sta_bw > sta->sta.bandwidth) {
-		sta->sta.bandwidth = new_sta_bw;
-		rate_control_rate_update(local, sband, sta,
-					 IEEE80211_RC_BW_CHANGED);
-	}
-
 	return 0;
 }
 
@@ -1174,10 +1140,6 @@ 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
@@ -1186,48 +1148,6 @@ 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,
@@ -1238,13 +1158,6 @@ 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;
 	}