wireless: add check of field VHT Extended NSS BW Capable for 160/80+80 MHz setting

Table 9-251—Supported VHT-MCS and NSS Set subfields, it has subfield VHT Extended
NSS BW Capable, its definition is:
Indicates whether the STA is capable of interpreting the Extended NSS BW
Support subfield of the VHT Capabilities Information field.

This patch is to add check for the subfield.
Signed-off-by: NWen Gong <wgong@codeaurora.org>
Link: https://lore.kernel.org/r/20210524033624.16993-1-wgong@codeaurora.orgSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

net/wireless/chan.c

@@ -942,7 +942,7 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 	struct ieee80211_sta_vht_cap *vht_cap;
 	struct ieee80211_edmg *edmg_cap;
 	u32 width, control_freq, cap;
-	bool support_80_80 = false;
+	bool ext_nss_cap, support_80_80 = false;
 
 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 		return false;
@@ -950,6 +950,8 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
 	edmg_cap = &wiphy->bands[chandef->chan->band]->edmg_cap;
+	ext_nss_cap = __le16_to_cpu(vht_cap->vht_mcs.tx_highest) &
+			IEEE80211_VHT_EXT_NSS_BW_CAPABLE;
 
 	if (edmg_cap->channels &&
 	    !cfg80211_edmg_usable(wiphy,
@@ -1015,7 +1017,8 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 			(cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ) ||
 			(cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
 			 cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) ||
-			u32_get_bits(cap, IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) > 1;
+			(ext_nss_cap &&
+			 u32_get_bits(cap, IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) > 1);
 		if (chandef->chan->band != NL80211_BAND_6GHZ && !support_80_80)
 			return false;
 		fallthrough;
@@ -1037,7 +1040,8 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ &&
-		    !(vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK))
+		    !(ext_nss_cap &&
+		      (vht_cap->cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK)))
 			return false;
 		break;
 	default: