ath5k: preserve higher order bits when setting mac address

In some cases we would like to set the mac address without changing
the operating mode.  However, Atheros cards store PCU data in the high
16 bits of the mac address register.  Change ath5k_hw_set_lladdr() to
not clobber the PCU settings.

Changes-licensed-under: ISC
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath5k/pcu.c

@@ -267,24 +267,23 @@ void ath5k_hw_get_lladdr(struct ath5k_hw *ah, u8 *mac)
  * @mac: The card's mac address
  *
  * Set station id on hw using the provided mac address
- *
- * NOTE: This is only called during attach, don't call it
- * on reset because it overwrites all AR5K_STA_ID1 settings.
- * We have set_opmode (above) for reset.
  */
 int ath5k_hw_set_lladdr(struct ath5k_hw *ah, const u8 *mac)
 {
 	u32 low_id, high_id;
+	u32 pcu_reg;
 
 	ATH5K_TRACE(ah->ah_sc);
 	/* Set new station ID */
 	memcpy(ah->ah_sta_id, mac, ETH_ALEN);
 
+	pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
+
 	low_id = AR5K_LOW_ID(mac);
 	high_id = AR5K_HIGH_ID(mac);
 
 	ath5k_hw_reg_write(ah, low_id, AR5K_STA_ID0);
-	ath5k_hw_reg_write(ah, high_id, AR5K_STA_ID1);
+	ath5k_hw_reg_write(ah, pcu_reg | high_id, AR5K_STA_ID1);
 
 	return 0;
 }