iwlwifi: use antenna information in EEPROM

The valid tx/rx antenna information is part of EEPROM, so use it
to configure the device.

For few cases, the EEPROM did not reflect the correct antenna, but
it is too late to modify the EEPROM, so overwrite with .cfg parameters

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c b/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c
index 8a4d3acb9b79..dbada761624d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c
@@ -251,6 +251,7 @@ err:
 int iwl_eeprom_check_sku(struct iwl_priv *priv)
 {
         u16 eeprom_sku;
+        u16 radio_cfg;
 
         eeprom_sku = iwl_eeprom_query16(priv, EEPROM_SKU_CAP);
 
@@ -266,6 +267,25 @@ int iwl_eeprom_check_sku(struct iwl_priv *priv)
 
         IWL_INFO(priv, "Device SKU: 0X%x\n", priv->cfg->sku);
 
+        if (!priv->cfg->valid_tx_ant && !priv->cfg->valid_rx_ant) {
+                /* not using .cfg overwrite */
+                radio_cfg = iwl_eeprom_query16(priv, EEPROM_RADIO_CONFIG);
+                priv->cfg->valid_tx_ant = EEPROM_RF_CFG_TX_ANT_MSK(radio_cfg);
+                priv->cfg->valid_rx_ant = EEPROM_RF_CFG_TX_ANT_MSK(radio_cfg);
+                if (!priv->cfg->valid_tx_ant || !priv->cfg->valid_rx_ant) {
+                        IWL_ERR(priv, "Invalid chain (0X%x, 0X%x)\n",
+                                priv->cfg->valid_tx_ant,
+                                priv->cfg->valid_rx_ant);
+                        return -EINVAL;
+                }
+                IWL_INFO(priv, "Valid Tx ant: 0X%x, Valid Rx ant: 0X%x\n",
+                         priv->cfg->valid_tx_ant, priv->cfg->valid_rx_ant);
+        }
+        /*
+         * for some special cases,
+         * EEPROM did not reflect the correct antenna setting
+         * so overwrite the valid tx/rx antenna from .cfg
+         */
         return 0;
 }