mac80211: Don't merge with the same BSSID

It was not a good idea to do a TSF reset on strange IBSS merges to the same BSSID. For example it will break the TSF sync of ath9k completely and it is unnecessary as all hardware I have tested do a TSF sync to a higher value automatically and IBSS merges are only done to higher TSF values. It only need a TSF reset to accept a lower value, when the IBSS network is changed manually.

Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index aa8937c..7a944ca 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -291,6 +291,10 @@
 				sdata->u.ibss.ssid_len))
 		goto put_bss;
 
+	/* same BSSID */
+	if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
+		goto put_bss;
+
 	if (rx_status->flag & RX_FLAG_TSFT) {
 		/*
 		 * For correct IBSS merging we need mactime; since mactime is