From 44c2cedcd938a24b4a75d3f0c02e64421751a41f Mon Sep 17 00:00:00 2001
From: Luca Coelho <luciano.coelho@intel.com>
Date: Fri, 5 May 2017 16:11:24 +0300
Subject: [PATCH 080/146] iwlwifi: mvm: reset the HW before dumping if HW error
 is detected
Git-commit: 6b54ebf73b3e5adc2cab3abc6cb37ca66fa74ae2
Patch-mainline: v4.13-rc1
References: FATE#322675

If the hardware is stuck, we can't read any of the memory we need to
dump it, so we end up printing only 0xa5a5a5a5, which is useless.

To solve this, poke the hardware by triggering a reset and re-enabling
the clocks if we detect a HW error.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c | 32 ++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index 264b270012a5..51ad0d56efe1 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -69,6 +69,7 @@
 #include "iwl-debug.h"
 #include "iwl-io.h"
 #include "iwl-prph.h"
+#include "iwl-csr.h"
 #include "fw-dbg.h"
 #include "mvm.h"
 #include "fw-api-rs.h"
@@ -497,6 +498,7 @@ static void iwl_mvm_dump_lmac_error_log(struct iwl_mvm *mvm, u32 base)
 {
 	struct iwl_trans *trans = mvm->trans;
 	struct iwl_error_event_table table;
+	u32 val;
 
 	if (mvm->cur_ucode == IWL_UCODE_INIT) {
 		if (!base)
@@ -515,6 +517,36 @@ static void iwl_mvm_dump_lmac_error_log(struct iwl_mvm *mvm, u32 base)
 		return;
 	}
 
+	/* check if there is a HW error */
+	val = iwl_trans_read_mem32(trans, base);
+	if (((val & ~0xf) == 0xa5a5a5a0) || ((val & ~0xf) == 0x5a5a5a50)) {
+		int err;
+
+		IWL_ERR(trans, "HW error, resetting before reading\n");
+
+		/* reset the device */
+		iwl_set_bit(trans, CSR_RESET, CSR_RESET_REG_FLAG_SW_RESET);
+		usleep_range(1000, 2000);
+
+		/* set INIT_DONE flag */
+		iwl_set_bit(trans, CSR_GP_CNTRL,
+			    CSR_GP_CNTRL_REG_FLAG_INIT_DONE);
+
+		/* and wait for clock stabilization */
+		if (trans->cfg->device_family == IWL_DEVICE_FAMILY_8000)
+			udelay(2);
+
+		err = iwl_poll_bit(trans, CSR_GP_CNTRL,
+				   CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY,
+				   CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY,
+				   25000);
+		if (err < 0) {
+			IWL_DEBUG_INFO(trans,
+				       "Failed to reset the card for the dump\n");
+			return;
+		}
+	}
+
 	iwl_trans_read_mem_bytes(trans, base, &table, sizeof(table));
 
 	if (ERROR_START_OFFSET <= table.valid * ERROR_ELEM_SIZE) {
-- 
2.12.3