wifi: mac80211: disallow drivers with HT wider than HE

To simplify the code in the next patch, disallow drivers
supporting 40 MHz in HT but not HE, since we'd otherwise
have to track local maximum bandwidth per mode there.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240111181514.da15fe3214d2.I4df51ad2f4c844615c168bf9bdb498925b3c77d4@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/main.c

@@ -1119,8 +1119,26 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		supp_vht = supp_vht || sband->vht_cap.vht_supported;
 
 		for_each_sband_iftype_data(sband, i, iftd) {
+			u8 he_40_mhz_cap;
+
 			supp_he = supp_he || iftd->he_cap.has_he;
 			supp_eht = supp_eht || iftd->eht_cap.has_eht;
+
+			if (sband->band == NL80211_BAND_2GHZ)
+				he_40_mhz_cap =
+					IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_IN_2G;
+			else
+				he_40_mhz_cap =
+					IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_80MHZ_IN_5G;
+
+			/* currently no support for HE client where HT has 40 MHz but not HT */
+			if (iftd->he_cap.has_he &&
+			    iftd->types_mask & (BIT(NL80211_IFTYPE_STATION) |
+						BIT(NL80211_IFTYPE_P2P_CLIENT)) &&
+			    sband->ht_cap.ht_supported &&
+			    sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 &&
+			    !(iftd->he_cap.he_cap_elem.phy_cap_info[0] & he_40_mhz_cap))
+				return -EINVAL;
 		}
 
 		/* HT, VHT, HE require QoS, thus >= 4 queues */