mac80211: get correct default channel width for S1G

When deleting a channel context, mac80211 would assing
NL80211_CHAN_WIDTH_20_NOHT as the default channel width.
This is wrong in S1G however, so instead get the allowed
channel width for a given channel.

Fixes eg. configuring strange (20Mhz) width during a scan
on the S1G band.
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200922022818.15855-2-thomas@adapt-ip.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/chan.c

@@ -536,7 +536,14 @@ static void ieee80211_del_chanctx(struct ieee80211_local *local,
 
 	if (!local->use_chanctx) {
 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
-		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
+		/* S1G doesn't have 20MHz, so get the correct width for the
+		 * current channel.
+		 */
+		if (chandef->chan->band == NL80211_BAND_S1GHZ)
+			chandef->width =
+				ieee80211_s1g_channel_width(chandef->chan);
+		else
+			chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 		chandef->center_freq1 = chandef->chan->center_freq;
 		chandef->freq1_offset = chandef->chan->freq_offset;
 		chandef->center_freq2 = 0;