mac80211: don't always advertise remain-on-channel

Not all devices are really capable of implementing
remain-on-channel, even if it is implemented in SW,
as they can't necessarily deal with channel changes
while associated.

Remove the WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL and add
it only if either the driver has remain_on_channel
implemented in the driver/device.

Also add it to all drivers that advertise P2P right
now since those definitely have to have it working.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -713,7 +713,8 @@ static void ath9k_set_hw_capab(struct ath9k_htc_priv *priv,
 
 	hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;
 
-	hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
+	hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN |
+			    WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
 	hw->queues = 4;
 	hw->channel_change_time = 5000;

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

@@ -678,6 +678,7 @@ void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
 
 	hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
 	hw->wiphy->flags |= WIPHY_FLAG_SUPPORTS_TDLS;
+	hw->wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
 	hw->queues = 4;
 	hw->max_rates = 4;

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

@@ -355,6 +355,8 @@ static int carl9170_fw(struct ar9170 *ar, const __u8 *data, size_t len)
 
 	ar->hw->wiphy->interface_modes |= if_comb_types;
 
+	ar->hw->wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
+
 #undef SUPPORTED
 	return carl9170_fw_tx_sequence(ar);
 }

drivers/net/wireless/mac80211_hwsim.c

@@ -1791,7 +1791,8 @@ static int __init init_mac80211_hwsim(void)
 			    IEEE80211_HW_SUPPORTS_DYNAMIC_SMPS |
 			    IEEE80211_HW_AMPDU_AGGREGATION;
 
-		hw->wiphy->flags |= WIPHY_FLAG_SUPPORTS_TDLS;
+		hw->wiphy->flags |= WIPHY_FLAG_SUPPORTS_TDLS |
+				    WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
 		/* ask mac80211 to reserve space for magic */
 		hw->vif_data_size = sizeof(struct hwsim_vif_priv);

drivers/net/wireless/wl12xx/main.c

@@ -5242,7 +5242,8 @@ static int wl1271_init_ieee80211(struct wl1271 *wl)
 	wl->hw->wiphy->max_sched_scan_ie_len = WL1271_CMD_TEMPL_MAX_SIZE -
 		sizeof(struct ieee80211_header);
 
-	wl->hw->wiphy->flags |= WIPHY_FLAG_AP_UAPSD;
+	wl->hw->wiphy->flags |= WIPHY_FLAG_AP_UAPSD |
+				WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
 	/* make sure all our channels fit in the scanned_ch bitmask */
 	BUILD_BUG_ON(ARRAY_SIZE(wl1271_channels) +

net/mac80211/main.c

@@ -557,8 +557,10 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 			WIPHY_FLAG_4ADDR_AP |
 			WIPHY_FLAG_4ADDR_STATION |
 			WIPHY_FLAG_REPORTS_OBSS |
-			WIPHY_FLAG_OFFCHAN_TX |
-			WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
+			WIPHY_FLAG_OFFCHAN_TX;
+
+	if (ops->remain_on_channel)
+		wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
 	wiphy->features = NL80211_FEATURE_SK_TX_STATUS |
 			  NL80211_FEATURE_HT_IBSS;