iwlwifi: make scan antenna forcing more generic

Some future hardware will also require some antenna
overrides so make the current logic more generic;
right now it is semantically based on a workaround
for off-channel reception but the reasons for the
new antenna overrides will be different.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

drivers/net/wireless/iwlwifi/iwl-4965.c

@@ -2261,8 +2261,13 @@ struct iwl_cfg iwl4965_agn_cfg = {
 	.plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 	.monitor_recover_period = IWL_MONITORING_PERIOD,
 	.temperature_kelvin = true,
-	.off_channel_workaround = true,
 	.max_event_log_size = 512,
+
+	/*
+	 * Force use of chains B and C for scan RX on 5 GHz band
+	 * because the device has off-channel reception on chain A.
+	 */
+	.scan_antennas[IEEE80211_BAND_5GHZ] = ANT_BC,
 };
 
 /* Module firmware */

drivers/net/wireless/iwlwifi/iwl-agn-lib.c

@@ -1405,13 +1405,6 @@ void iwlagn_request_scan(struct iwl_priv *priv)
 		 * detect transmissions.
 		 */
 		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
-
-		/* Force use of chains B and C (0x6) for scan Rx
-		 * Avoid A (0x1) for the device has off-channel reception
-		 * on A-band.
-		 */
-		if (priv->cfg->off_channel_workaround)
-			rx_ant = ANT_BC;
 		break;
 	default:
 		IWL_WARN(priv, "Invalid scan band count\n");
@@ -1420,6 +1413,9 @@ void iwlagn_request_scan(struct iwl_priv *priv)
 
 	band = priv->scan_band;
 
+	if (priv->cfg->scan_antennas[band])
+		rx_ant = priv->cfg->scan_antennas[band];
+
 	priv->scan_tx_ant[band] =
 			iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);

drivers/net/wireless/iwlwifi/iwl-core.h

@@ -318,8 +318,8 @@ struct iwl_cfg {
 	/* timer period for monitor the driver queues */
 	u32 monitor_recover_period;
 	bool temperature_kelvin;
-	bool off_channel_workaround;
 	u32 max_event_log_size;
+	u8 scan_antennas[IEEE80211_NUM_BANDS];
 };
 
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