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, 39 insertions, 0 deletions

diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c
index 1606aa165d5f..0fc9a2fb8d53 100644
--- a/net/mac80211/vht.c
+++ b/net/mac80211/vht.c
@@ -27,6 +27,10 @@ void ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
         if (!vht_cap_ie || !sband->vht_cap.vht_supported)
                 return;
 
+        /* A VHT STA must support 40 MHz */
+        if (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40))
+                return;
+
         vht_cap->vht_supported = true;
 
         vht_cap->cap = le32_to_cpu(vht_cap_ie->vht_cap_info);
@@ -34,4 +38,39 @@ void ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
         /* Copy peer MCS info, the driver might need them. */
         memcpy(&vht_cap->vht_mcs, &vht_cap_ie->supp_mcs,
                sizeof(struct ieee80211_vht_mcs_info));
+
+        sta->sta.bandwidth = ieee80211_sta_cur_vht_bw(sta);
+}
+
+enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct sta_info *sta)
+{
+        struct ieee80211_sub_if_data *sdata = sta->sdata;
+        u32 cap = sta->sta.vht_cap.cap;
+
+        if (!sta->sta.vht_cap.vht_supported)
+                return sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
+                                IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
+
+        /* TODO: handle VHT opmode notification data */
+
+        switch (sdata->vif.bss_conf.chandef.width) {
+        default:
+                WARN_ON_ONCE(1);
+                /* fall through */
+        case NL80211_CHAN_WIDTH_20_NOHT:
+        case NL80211_CHAN_WIDTH_20:
+        case NL80211_CHAN_WIDTH_40:
+                return sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
+                                IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
+        case NL80211_CHAN_WIDTH_160:
+                if (cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ)
+                        return IEEE80211_STA_RX_BW_160;
+                /* fall through */
+        case NL80211_CHAN_WIDTH_80P80:
+                if (cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
+                        return IEEE80211_STA_RX_BW_160;
+                /* fall through */
+        case NL80211_CHAN_WIDTH_80:
+                return IEEE80211_STA_RX_BW_80;
+        }
 }