iwlwifi: pcie: don't count on the FW to set persistence mode

Apparently the FW can't set the persistence in all flows. Don't count
on the FW setting it in AX210 devices or above either to avoid
potential resets on resume.

Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200529092401.5405db448555.Ie3c110932ebbd5b6aca99938a5e0a1e4dfbaa848@changeid

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

@@ -5,10 +5,9 @@
  *
  * GPL LICENSE SUMMARY
  *
- * Copyright(c) 2007 - 2015 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2018 - 2019 Intel Corporation
+ * Copyright(c) 2007 - 2015, 2018 - 2020 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -28,10 +27,9 @@
  *
  * BSD LICENSE
  *
- * Copyright(c) 2005 - 2015 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2018 - 2019 Intel Corporation
+ * Copyright(c) 2007 - 2015, 2018 - 2020 Intel Corporation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -1495,14 +1493,10 @@ static int iwl_trans_pcie_d3_suspend(struct iwl_trans *trans, bool test,
 	int ret;
 	struct iwl_trans_pcie *trans_pcie =  IWL_TRANS_GET_PCIE_TRANS(trans);
 
-	/*
-	 * Family IWL_DEVICE_FAMILY_AX210 and above persist mode is set by FW.
-	 */
-	if (!reset && trans->trans_cfg->device_family < IWL_DEVICE_FAMILY_AX210) {
+	if (!reset)
 		/* Enable persistence mode to avoid reset */
 		iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
 			    CSR_HW_IF_CONFIG_REG_PERSIST_MODE);
-	}
 
 	if (trans->trans_cfg->device_family >= IWL_DEVICE_FAMILY_AX210) {
 		iwl_write_umac_prph(trans, UREG_DOORBELL_TO_ISR6,