ath9k_hw: remove defunct ad-hoc mode ATIM window handling code

The hardware does not have support for ATIM processing, and the driver
does not set up ah->atim_window anywhere. Additionally, the code can
clobber the timer used by P2P powersave.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -486,7 +486,6 @@ static void ath9k_hw_init_defaults(struct ath_hw *ah)
 	ah->hw_version.magic = AR5416_MAGIC;
 	ah->hw_version.subvendorid = 0;
 
-	ah->atim_window = 0;
 	ah->sta_id1_defaults =
 		AR_STA_ID1_CRPT_MIC_ENABLE |
 		AR_STA_ID1_MCAST_KSRCH;
@@ -2266,9 +2265,6 @@ void ath9k_hw_beaconinit(struct ath_hw *ah, u32 next_beacon, u32 beacon_period)
 	case NL80211_IFTYPE_ADHOC:
 		REG_SET_BIT(ah, AR_TXCFG,
 			    AR_TXCFG_ADHOC_BEACON_ATIM_TX_POLICY);
-		REG_WRITE(ah, AR_NEXT_NDP_TIMER, next_beacon +
-			  TU_TO_USEC(ah->atim_window ? ah->atim_window : 1));
-		flags |= AR_NDP_TIMER_EN;
 	case NL80211_IFTYPE_MESH_POINT:
 	case NL80211_IFTYPE_AP:
 		REG_WRITE(ah, AR_NEXT_TBTT_TIMER, next_beacon);
@@ -2289,7 +2285,6 @@ void ath9k_hw_beaconinit(struct ath_hw *ah, u32 next_beacon, u32 beacon_period)
 	REG_WRITE(ah, AR_BEACON_PERIOD, beacon_period);
 	REG_WRITE(ah, AR_DMA_BEACON_PERIOD, beacon_period);
 	REG_WRITE(ah, AR_SWBA_PERIOD, beacon_period);
-	REG_WRITE(ah, AR_NDP_PERIOD, beacon_period);
 
 	REGWRITE_BUFFER_FLUSH(ah);
 

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

@@ -776,7 +776,6 @@ struct ath_hw {
 	u32 txurn_interrupt_mask;
 	atomic_t intr_ref_cnt;
 	bool chip_fullsleep;
-	u32 atim_window;
 	u32 modes_index;
 
 	/* Calibration */