--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1228,6 +1228,11 @@ void ath9k_hw_init_global_settings(struc
 	/* As defined by IEEE 802.11-2007 17.3.8.6 */
 	slottime = ah->slottime + 3 * ah->coverage_class;
 	acktimeout = slottime + sifstime;
+
+	/* Workaround for a hw issue */
+	if (conf->channel && conf->channel->band == IEEE80211_BAND_2GHZ)
+		acktimeout = max(64, acktimeout);
+
 	ath9k_hw_setslottime(ah, slottime);
 	ath9k_hw_set_ack_timeout(ah, acktimeout);
 	ath9k_hw_set_cts_timeout(ah, acktimeout);