b43(legacy): include full timestamp in beacon frames

Having the full RX timestamp in beacons is necessary for IBSS
merge to work properly so extend the 16-bit timestamp to the
full 64 bits for beacon frames (as well as when monitor mode
is active.)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index 4014b6c..187c11b 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -589,12 +589,16 @@
 	status.antenna = !!(phystat0 & B43_RX_PHYST0_ANT);
 
 	/*
-	 * If monitors are present get full 64-bit timestamp. This
-	 * code assumes we get to process the packet within 16 bits
-	 * of timestamp, i.e. about 65 milliseconds after the PHY
-	 * received the first symbol.
+	 * All frames on monitor interfaces and beacons always need a full
+	 * 64-bit timestamp. Monitor interfaces need it for diagnostic
+	 * purposes and beacons for IBSS merging.
+	 * This code assumes we get to process the packet within 16 bits
+	 * of timestamp, i.e. about 65 milliseconds after the PHY received
+	 * the first symbol.
 	 */
-	if (dev->wl->radiotap_enabled) {
+	if (((fctl & (IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE))
+	    == (IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON)) ||
+	    dev->wl->radiotap_enabled) {
 		u16 low_mactime_now;
 
 		b43_tsf_read(dev, &status.mactime);