mac80211: add a flag to indicate CCK support for HT clients

brcm80211 cannot handle sending frames with CCK rates as part of an
A-MPDU session. Other drivers may have issues too. Set the flag in all
drivers that have been tested with CCK rates.

This fixes a reported brcmsmac regression introduced in
commit ef47a5e4f1aaf1d0e2e6875e34b2c9595897bef6
"mac80211/minstrel_ht: fix cck rate sampling"

Cc: stable@vger.kernel.org # 3.10
Reported-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/ath/ath9k/init.c

@@ -802,7 +802,8 @@ void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
 		IEEE80211_HW_PS_NULLFUNC_STACK |
 		IEEE80211_HW_SPECTRUM_MGMT |
 		IEEE80211_HW_REPORTS_TX_ACK_STATUS |
-		IEEE80211_HW_SUPPORTS_RC_TABLE;
+		IEEE80211_HW_SUPPORTS_RC_TABLE |
+		IEEE80211_HW_SUPPORTS_HT_CCK_RATES;
 
 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT) {
 		hw->flags |= IEEE80211_HW_AMPDU_AGGREGATION;

drivers/net/wireless/ath/carl9170/main.c

@@ -1860,7 +1860,8 @@ void *carl9170_alloc(size_t priv_size)
 		     IEEE80211_HW_PS_NULLFUNC_STACK |
 		     IEEE80211_HW_NEED_DTIM_BEFORE_ASSOC |
 		     IEEE80211_HW_SUPPORTS_RC_TABLE |
-		     IEEE80211_HW_SIGNAL_DBM;
+		     IEEE80211_HW_SIGNAL_DBM |
+		     IEEE80211_HW_SUPPORTS_HT_CCK_RATES;
 
 	if (!modparam_noht) {
 		/*

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -6133,7 +6133,8 @@ static int rt2800_probe_hw_mode(struct rt2x00_dev *rt2x00dev)
 	    IEEE80211_HW_SUPPORTS_PS |
 	    IEEE80211_HW_PS_NULLFUNC_STACK |
 	    IEEE80211_HW_AMPDU_AGGREGATION |
-	    IEEE80211_HW_REPORTS_TX_ACK_STATUS;
+	    IEEE80211_HW_REPORTS_TX_ACK_STATUS |
+	    IEEE80211_HW_SUPPORTS_HT_CCK_RATES;
 
 	/*
 	 * Don't set IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING for USB devices

include/net/mac80211.h

@@ -1499,6 +1499,7 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_SUPPORTS_RC_TABLE			= 1<<24,
 	IEEE80211_HW_P2P_DEV_ADDR_FOR_INTF		= 1<<25,
 	IEEE80211_HW_TIMING_BEACON_ONLY			= 1<<26,
+	IEEE80211_HW_SUPPORTS_HT_CCK_RATES		= 1<<27,
 };
 
 /**

net/mac80211/rc80211_minstrel_ht.c

@@ -828,6 +828,9 @@ minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 	if (sband->band != IEEE80211_BAND_2GHZ)
 		return;
 
+	if (!(mp->hw->flags & IEEE80211_HW_SUPPORTS_HT_CCK_RATES))
+		return;
+
 	mi->cck_supported = 0;
 	mi->cck_supported_short = 0;
 	for (i = 0; i < 4; i++) {