mac80211: s1g: choose scanning width based on frequency

An S1G BSS can beacon at either 1 or 2 MHz and the channel
width is unique to a given frequency. Ignore scan channel
width for now and use the allowed channel width.
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200922022818.15855-3-thomas@adapt-ip.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/scan.c

@@ -909,6 +909,17 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 	local->scan_chandef.center_freq1 = chan->center_freq;
 	local->scan_chandef.freq1_offset = chan->freq_offset;
 	local->scan_chandef.center_freq2 = 0;
+
+	/* For scanning on the S1G band, ignore scan_width (which is constant
+	 * across all channels) for now since channel width is specific to each
+	 * channel. Detect the required channel width here and likely revisit
+	 * later. Maybe scan_width could be used to build the channel scan list?
+	 */
+	if (chan->band == NL80211_BAND_S1GHZ) {
+		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
+		goto set_channel;
+	}
+
 	switch (scan_req->scan_width) {
 	case NL80211_BSS_CHAN_WIDTH_5:
 		local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
@@ -929,8 +940,14 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 		else
 			local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 		break;
+	case NL80211_BSS_CHAN_WIDTH_1:
+	case NL80211_BSS_CHAN_WIDTH_2:
+		/* shouldn't get here, S1G handled above */
+		WARN_ON(1);
+		break;
 	}
 
+set_channel:
 	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 		skip = 1;