ath9k: validate eeprom chainmask settings, some Ubiquiti devices (and maybe others) contain bogus data, which breaks wifi

SVN-Revision: 27688

package/mac80211/patches/580-ath9k_fixup_chainmask.patch

@@ -0,0 +1,51 @@
+--- a/drivers/net/wireless/ath/ath9k/hw.c
++++ b/drivers/net/wireless/ath/ath9k/hw.c
+@@ -2007,12 +2007,22 @@ EXPORT_SYMBOL(ath9k_hw_set_sta_beacon_ti
+ /* HW Capabilities */
+ /*******************/
+ 
++static u8 fixup_chainmask(u8 chip_chainmask, u8 eeprom_chainmask)
++{
++	eeprom_chainmask &= chip_chainmask;
++	if (eeprom_chainmask)
++		return eeprom_chainmask;
++	else
++		return chip_chainmask;
++}
++
+ int ath9k_hw_fill_cap_info(struct ath_hw *ah)
+ {
+ 	struct ath9k_hw_capabilities *pCap = &ah->caps;
+ 	struct ath_regulatory *regulatory = ath9k_hw_regulatory(ah);
+ 	struct ath_common *common = ath9k_hw_common(ah);
+ 	struct ath_btcoex_hw *btcoex_hw = &ah->btcoex_hw;
++	unsigned int chip_chainmask;
+ 
+ 	u16 eeval;
+ 	u8 ant_div_ctl1, tx_chainmask, rx_chainmask;
+@@ -2049,6 +2059,15 @@ int ath9k_hw_fill_cap_info(struct ath_hw
+ 	if (eeval & AR5416_OPFLAGS_11G)
+ 		pCap->hw_caps |= ATH9K_HW_CAP_2GHZ;
+ 
++	if (AR_SREV_9485(ah) || AR_SREV_9285(ah) || AR_SREV_9330(ah))
++		chip_chainmask = 1;
++	else if (!AR_SREV_9280_20_OR_LATER(ah))
++		chip_chainmask = 7;
++	else if (!AR_SREV_9300_20_OR_LATER(ah) || AR_SREV_9340(ah))
++		chip_chainmask = 3;
++	else
++		chip_chainmask = 7;
++
+ 	pCap->tx_chainmask = ah->eep_ops->get_eeprom(ah, EEP_TX_MASK);
+ 	/*
+ 	 * For AR9271 we will temporarilly uses the rx chainmax as read from
+@@ -2065,6 +2084,9 @@ int ath9k_hw_fill_cap_info(struct ath_hw
+ 		/* Use rx_chainmask from EEPROM. */
+ 		pCap->rx_chainmask = ah->eep_ops->get_eeprom(ah, EEP_RX_MASK);
+ 
++	pCap->tx_chainmask = fixup_chainmask(chip_chainmask, pCap->tx_chainmask);
++	pCap->rx_chainmask = fixup_chainmask(chip_chainmask, pCap->rx_chainmask);
++
+ 	ah->misc_mode |= AR_PCU_MIC_NEW_LOC_ENA;
+ 
+ 	/* enable key search for every frame in an aggregate */