From b8a7547d77782ba1d403f2417be9453a3a256e14 Mon Sep 17 00:00:00 2001
From: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Date: Wed, 5 Dec 2018 08:48:26 +0200
Subject: [PATCH] iwlwifi: fix send hcmd timeout recovery flow
Git-commit: b8a7547d77782ba1d403f2417be9453a3a256e14
Patch-mainline: v5.1-rc1
References: bsc#1129770

Both iwl_trans_fw_error and iwl_force_nmi initiate async recovery flow.
Calling them both is redundant and causing a race.

Solve this by removing the call to iwl_trans_fw_error.

Signed-off-by: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Fixes: cfadc3ffccd5 ("iwlwifi: pcie: stop the firmware when we restart it")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/wireless/intel/iwlwifi/iwl-trans.h     |    3 ++
 drivers/net/wireless/intel/iwlwifi/pcie/internal.h |    1 
 drivers/net/wireless/intel/iwlwifi/pcie/trans.c    |   25 +++++++++++++++++++++
 drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c  |    6 ++---
 drivers/net/wireless/intel/iwlwifi/pcie/tx.c       |    5 +---
 5 files changed, 34 insertions(+), 6 deletions(-)

--- a/drivers/net/wireless/intel/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-trans.h
@@ -671,6 +671,9 @@ enum iwl_plat_pm_mode {
  */
 #define IWL_TRANS_IDLE_TIMEOUT 2000
 
+/* Max time to wait for nmi interrupt */
+#define IWL_TRANS_NMI_TIMEOUT (HZ / 4)
+
 /**
  * struct iwl_trans - transport common data
  *
--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
@@ -777,6 +777,7 @@ static inline void __iwl_trans_pcie_set_
 }
 
 void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state);
+void iwl_trans_sync_nmi(struct iwl_trans *trans);
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 int iwl_trans_pcie_dbgfs_register(struct iwl_trans *trans);
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -3205,3 +3205,28 @@ out_no_pci:
 	iwl_trans_free(trans);
 	return ERR_PTR(ret);
 }
+
+void iwl_trans_sync_nmi(struct iwl_trans *trans)
+{
+	unsigned long timeout = jiffies + IWL_TRANS_NMI_TIMEOUT;
+
+	iwl_disable_interrupts(trans);
+	iwl_force_nmi(trans);
+	while (time_after(timeout, jiffies)) {
+		u32 inta_hw = iwl_read32(trans,
+					 CSR_MSIX_HW_INT_CAUSES_AD);
+
+		/* Error detected by uCode */
+		if (inta_hw & MSIX_HW_INT_CAUSES_REG_SW_ERR) {
+			/* Clear causes register */
+			iwl_write32(trans, CSR_MSIX_HW_INT_CAUSES_AD,
+				    inta_hw &
+				    MSIX_HW_INT_CAUSES_REG_SW_ERR);
+			break;
+		}
+
+		mdelay(1);
+	}
+	iwl_enable_interrupts(trans);
+	iwl_trans_fw_error(trans);
+}
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -6,7 +6,7 @@
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2017 Intel Deutschland GmbH
- * Copyright(c) 2018        Intel Corporation
+ * Copyright(c) 2018 - 2019 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
@@ -20,7 +20,7 @@
  * BSD LICENSE
  *
  * Copyright(c) 2017 Intel Deutschland GmbH
- * Copyright(c) 2018        Intel Corporation
+ * Copyright(c) 2018 - 2019 Intel Corporation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -851,9 +851,7 @@ static int iwl_pcie_gen2_send_hcmd_sync(
 			       cmd_str);
 		ret = -ETIMEDOUT;
 
-		iwl_force_nmi(trans);
-		iwl_trans_fw_error(trans);
-
+		iwl_trans_sync_nmi(trans);
 		goto cancel;
 	}
 
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -3,7 +3,7 @@
  * Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2018 Intel Corporation
+ * Copyright(c) 2018 - 2019 Intel Corporation
  *
  * Portions of this file are derived from the ipw3945 project, as well
  * as portions of the ieee80211 subsystem header files.
@@ -1883,9 +1884,7 @@ static int iwl_pcie_send_hcmd_sync(struc
 			       iwl_get_cmd_string(trans, cmd->id));
 		ret = -ETIMEDOUT;
 
-		iwl_force_nmi(trans);
-		iwl_trans_fw_error(trans);
-
+		iwl_trans_sync_nmi(trans);
 		goto cancel;
 	}