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, 8 insertions, 15 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 2db1f2b..40b71df 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -496,33 +496,26 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 		if (sta && elems->ht_operation && elems->ht_cap_elem &&
 		    sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
 			/* we both use HT */
-			struct ieee80211_sta_ht_cap sta_ht_cap_new;
+			struct ieee80211_ht_cap htcap_ie;
 			struct cfg80211_chan_def chandef;
 
 			ieee80211_ht_oper_to_chandef(channel,
 						     elems->ht_operation,
 						     &chandef);
 
-			ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
-							  elems->ht_cap_elem,
-							  &sta_ht_cap_new);
+			memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
 
 			/*
 			 * fall back to HT20 if we don't use or use
 			 * the other extension channel
 			 */
-			if (chandef.width != NL80211_CHAN_WIDTH_40 ||
-			    cfg80211_get_chandef_type(&chandef) !=
+			if (cfg80211_get_chandef_type(&chandef) !=
 						sdata->u.ibss.channel_type)
-				sta_ht_cap_new.cap &=
-					~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
-
-			if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
-				   sizeof(sta_ht_cap_new))) {
-				memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
-				       sizeof(sta_ht_cap_new));
-				rates_updated = true;
-			}
+				htcap_ie.cap_info &=
+					cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
+
+			rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
+						sdata, sband, &htcap_ie, sta);
 		}
 
 		if (sta && rates_updated) {