iwlwifi: pcie: only apply retention workaround on 9000-series A-step

Due to a hardware issue, certain power saving had to be
disabled. However, this issue was fixed in B-step, so the
workaround only needs to apply to A-step.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/pcie/rx.c

@@ -761,6 +761,15 @@ static void iwl_pcie_rx_hw_init(struct iwl_trans *trans, struct iwl_rxq *rxq)
 
 void iwl_pcie_enable_rx_wake(struct iwl_trans *trans, bool enable)
 {
+	if (trans->cfg->device_family != IWL_DEVICE_FAMILY_9000)
+		return;
+
+	if (CSR_HW_REV_STEP(trans->hw_rev) != SILICON_A_STEP)
+		return;
+
+	if (!trans->cfg->integrated)
+		return;
+
 	/*
 	 * Turn on the chicken-bits that cause MAC wakeup for RX-related
 	 * values.
@@ -768,12 +777,10 @@ void iwl_pcie_enable_rx_wake(struct iwl_trans *trans, bool enable)
 	 * bug where shadow registers are not in the retention list and their
 	 * value is lost when NIC powers down
 	 */
-	if (trans->cfg->integrated) {
 	iwl_set_bit(trans, CSR_MAC_SHADOW_REG_CTRL,
 		    CSR_MAC_SHADOW_REG_CTRL_RX_WAKE);
 	iwl_set_bit(trans, CSR_MAC_SHADOW_REG_CTL2,
 		    CSR_MAC_SHADOW_REG_CTL2_RX_WAKE);
-	}
 }
 
 static void iwl_pcie_rx_mq_hw_init(struct iwl_trans *trans)