--- /dev/null
+--- a/drivers/net/wireless/ath/ath9k/hw.c
++++ b/drivers/net/wireless/ath/ath9k/hw.c
+@@ -1229,6 +1229,11 @@ 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);