ath9k: Fix ASPM workaround usage

The PCIE Workaround register (AR_WA/0x4004) is used to handle
various hardware quirks. For AR9002 chips, AR_WA_D3_L1_DISABLE
is used to prevent the HW from automatically entering L1 state
when D3 is enforced.

AR_WA_D3_L1_DISABLE has to be enabled for a few AR9280 based
cards, mark them based on their PCI subdevice/subvendor IDs
and enforce it in ar9002_hw_configpcipowersave().

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 19b46c7..c9f787d 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -551,6 +551,11 @@
 		pCap->hw_caps |= ATH9K_HW_CAP_BT_ANT_DIV;
 		ath_info(common, "Set BT/WLAN RX diversity capability\n");
 	}
+
+	if (sc->driver_data & ATH9K_PCI_D3_L1_WAR) {
+		ah->config.pcie_waen = 0x0040473b;
+		ath_info(common, "Enable WAR for ASPM D3/L1\n");
+	}
 }
 
 static void ath9k_eeprom_request_cb(const struct firmware *eeprom_blob,