cfg80211: ibss: use 11a mandatory rates for 6GHz band operation

The default mandatory rates, ie. when not specified by user-space, is
determined by the band. Select 11a rateset for 6GHz band.
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Leon Zegers <leon.zegers@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Link: https://lore.kernel.org/r/1564745465-21234-8-git-send-email-arend.vanspriel@broadcom.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/ibss.c

@@ -104,13 +104,19 @@ int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
 		* use the mandatory rate set for 11b or
 		* 11a for maximum compatibility.
 		*/
-		struct ieee80211_supported_band *sband =
-			rdev->wiphy.bands[params->chandef.chan->band];
+		struct ieee80211_supported_band *sband;
+		enum nl80211_band band;
+		u32 flag;
 		int j;
-		u32 flag = params->chandef.chan->band == NL80211_BAND_5GHZ ?
-			IEEE80211_RATE_MANDATORY_A :
-			IEEE80211_RATE_MANDATORY_B;
 
+		band = params->chandef.chan->band;
+		if (band == NL80211_BAND_5GHZ ||
+		    band == NL80211_BAND_6GHZ)
+			flag = IEEE80211_RATE_MANDATORY_A;
+		else
+			flag = IEEE80211_RATE_MANDATORY_B;
+
+		sband = rdev->wiphy.bands[band];
 		for (j = 0; j < sband->n_bitrates; j++) {
 			if (sband->bitrates[j].flags & flag)
 				params->basic_rates |= BIT(j);