Index: sys/dev/usb/wlan/if_run.c
===================================================================
--- sys/dev/usb/wlan/if_run.c
+++ sys/dev/usb/wlan/if_run.c
@@ -431,6 +431,7 @@
 static void	run_usb_timeout_cb(void *);
 static void	run_reset_livelock(struct run_softc *);
 static void	run_enable_tsf_sync(struct run_softc *);
+static void	run_enable_tsf(struct run_softc *);
 static void	run_get_tsf(struct run_softc *, uint64_t *);
 static void	run_enable_mrr(struct run_softc *);
 static void	run_set_txpreamble(struct run_softc *);
@@ -2126,7 +2127,8 @@
 			tp = &vap->iv_txparms[ieee80211_chan2mode(ic->ic_curchan)];
 			if (tp->ucastrate == IEEE80211_FIXED_RATE_NONE)
 				ratectl |= bid;
-		}
+		} else
+			run_enable_tsf(sc);
 
 		/* turn link LED on */
 		run_set_leds(sc, RT2860_LED_RADIO |
@@ -5050,6 +5052,18 @@
 }
 
 static void
+run_enable_tsf(struct run_softc *sc)
+{
+	uint32_t tmp;
+
+	if (run_read(sc, RT2860_BCN_TIME_CFG, &tmp) == 0) {
+		tmp &= ~(RT2860_BCN_TX_EN | RT2860_TBTT_TIMER_EN);
+		tmp |= RT2860_TSF_TIMER_EN;
+		run_write(sc, RT2860_BCN_TIME_CFG, tmp);
+	}
+}
+
+static void
 run_get_tsf(struct run_softc *sc, uint64_t *buf)
 {
 	run_read_region_1(sc, RT2860_TSF_TIMER_DW0, (uint8_t *)buf,