iwlwifi: pcie: stop the firmware when we restart it

In case the firmware didn't assert but we want to restart
it, e.g. we didn't get the reply for a host command, or the
Tx queues are stuck, we should stop the firmware by
provoking an interrupt. This allows to better debug the
firmware in these bad scenarios.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/pcie/tx.c

@@ -207,7 +207,7 @@ static void iwl_pcie_txq_stuck_timer(unsigned long data)
 		IWL_ERR(trans, "scratch %d = 0x%08x\n", i,
 			le32_to_cpu(txq->scratchbufs[i].scratch));
 
-	iwl_trans_fw_error(trans);
+	iwl_write_prph(trans, DEVICE_SET_NMI_REG, 1);
 }
 
 /*
@@ -1024,7 +1024,7 @@ static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx)
 		if (nfreed++ > 0) {
 			IWL_ERR(trans, "HCMD skipped: index (%d) %d %d\n",
 				idx, q->write_ptr, q->read_ptr);
-			iwl_trans_fw_error(trans);
+			iwl_write_prph(trans, DEVICE_SET_NMI_REG, 1);
 		}
 	}
 
@@ -1583,6 +1583,7 @@ static int iwl_pcie_send_hcmd_sync(struct iwl_trans *trans,
 			       get_cmd_string(trans_pcie, cmd->id));
 		ret = -ETIMEDOUT;
 
+		iwl_write_prph(trans, DEVICE_SET_NMI_REG, 1);
 		iwl_trans_fw_error(trans);
 
 		goto cancel;