ath9k_hw: add support for 8 AP mode interfaces

Also tweak beacon response times for better stability with the shorter
timer intervals.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -370,7 +370,7 @@ struct ath_vif {
  * number of beacon intervals, the game's up.
  */
 #define BSTUCK_THRESH           	9
-#define	ATH_BCBUF               	4
+#define	ATH_BCBUF               	8
 #define ATH_DEFAULT_BINTVAL     	100 /* TU */
 #define ATH_DEFAULT_BMISS_LIMIT 	10
 #define IEEE80211_MS_TO_TU(x)           (((x) * 1000) / 1024)

drivers/net/wireless/ath/ath9k/hw.c

@@ -437,8 +437,8 @@ static void ath9k_hw_init_config(struct ath_hw *ah)
 {
 	int i;
 
-	ah->config.dma_beacon_response_time = 2;
-	ah->config.sw_beacon_response_time = 10;
+	ah->config.dma_beacon_response_time = 1;
+	ah->config.sw_beacon_response_time = 6;
 	ah->config.additional_swba_backoff = 0;
 	ah->config.ack_6mb = 0x0;
 	ah->config.cwm_ignore_extcca = 0;