ath9k: fix TSF across hardware resets on AR913x

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21989 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/mac80211/patches/510-ar9100_tsf_preserve.patch

@@ -0,0 +1,39 @@
+--- a/drivers/net/wireless/ath/ath9k/hw.c
++++ b/drivers/net/wireless/ath/ath9k/hw.c
+@@ -1280,7 +1280,8 @@ int ath9k_hw_reset(struct ath_hw *ah, st
+ 	macStaId1 = REG_READ(ah, AR_STA_ID1) & AR_STA_ID1_BASE_RATE_11B;
+ 
+ 	/* For chips on which RTC reset is done, save TSF before it gets cleared */
+-	if (AR_SREV_9280(ah) && ah->eep_ops->get_eeprom(ah, EEP_OL_PWRCTRL))
++	if (AR_SREV_9100(ah) ||
++	    (AR_SREV_9280(ah) && ah->eep_ops->get_eeprom(ah, EEP_OL_PWRCTRL)))
+ 		tsf = ath9k_hw_gettsf64(ah);
+ 
+ 	saveLedState = REG_READ(ah, AR_CFG_LED) &
+@@ -1312,7 +1313,7 @@ int ath9k_hw_reset(struct ath_hw *ah, st
+ 	}
+ 
+ 	/* Restore TSF */
+-	if (tsf && AR_SREV_9280(ah) && ah->eep_ops->get_eeprom(ah, EEP_OL_PWRCTRL))
++	if (tsf)
+ 		ath9k_hw_settsf64(ah, tsf);
+ 
+ 	if (AR_SREV_9280_10_OR_LATER(ah))
+@@ -1325,6 +1326,17 @@ int ath9k_hw_reset(struct ath_hw *ah, st
+ 	if (r)
+ 		return r;
+ 
++	/*
++	 * Some AR91xx SoC devices frequently fail to accept TSF writes
++	 * right after the chip reset. When that happens, write a new
++	 * value after the initvals have been applied, with an offset
++	 * based on measured time differences
++	 */
++	if (AR_SREV_9100(ah) && (ath9k_hw_gettsf64(ah) < tsf)) {
++		tsf += 1500;
++		ath9k_hw_settsf64(ah, tsf);
++	}
++
+ 	/* Setup MFP options for CCMP */
+ 	if (AR_SREV_9280_20_OR_LATER(ah)) {
+ 		/* Mask Retry(b11), PwrMgt(b12), MoreData(b13) to 0 in mgmt