mac80211: stop toggling IEEE80211_HT_CAP_SUP_WIDTH_20_40

For VHT, many more bandwidth changes are possible. As a first
step, stop toggling the IEEE80211_HT_CAP_SUP_WIDTH_20_40 flag
in the HT capabilities and instead introduce a bandwidth field
indicating the currently usable bandwidth to transmit to the
station. Of course, make all drivers use it.

To achieve this, make ieee80211_ht_cap_ie_to_sta_ht_cap() get
the station as an argument, rather than the new capabilities,
so it can set up the new bandwidth field.

If the station is a VHT station and VHT bandwidth is in use,
also set the bandwidth accordingly.

Doing this allows us to get rid of the supports_40mhz flag as
the HT capabilities now reflect the true capability instead of
the current setting.

While at it, also fix ieee80211_ht_cap_ie_to_sta_ht_cap() to not
ignore HT cap overrides when MCS TX isn't supported (not that it
really happens...)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 10 insertions, 12 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 58b6e67ffbed..be1147286801 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -219,19 +219,20 @@ static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,
         mutex_lock(&local->sta_mtx);
         sta = sta_info_get(sdata, bssid);
 
-        WARN_ON_ONCE(!sta);
+        if (WARN_ON_ONCE(!sta)) {
+                mutex_unlock(&local->sta_mtx);
+                return changed;
+        }
 
-        if (sta && !sta->supports_40mhz)
+        if (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40))
                 disable_40 = true;
 
-        if (sta && (!reconfig ||
-                    (disable_40 != !(sta->sta.ht_cap.cap &
-                                        IEEE80211_HT_CAP_SUP_WIDTH_20_40)))) {
-
+        if (!reconfig ||
+            disable_40 != (sta->sta.bandwidth < IEEE80211_STA_RX_BW_40)) {
                 if (disable_40)
-                        sta->sta.ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+                        sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
                 else
-                        sta->sta.ht_cap.cap |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+                        sta->sta.bandwidth = ieee80211_sta_cur_vht_bw(sta);
 
                 rate_control_rate_update(local, sband, sta,
                                          IEEE80211_RC_BW_CHANGED);
@@ -2210,10 +2211,7 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata,
 
         if (elems.ht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_HT))
                 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
-                                elems.ht_cap_elem, &sta->sta.ht_cap);
-
-        sta->supports_40mhz =
-                sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+                                                  elems.ht_cap_elem, sta);
 
         if (elems.vht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,