iwlwifi: improve the flow when a NIC is disconnected

When the NIC is disconnected, we just can't do anything
besides seeking for help from the bus driver.  Dumping the
device's memory is not necessary and just bloats the logs
with unusable data.  Moreover, asking mac80211 to restart
the hardware is also useless.  Bypass all this.

Also, use the STATUS_TRANS_DEAD status bit instead of a
bool inside the transport layer. The advantage of this is
that now, the transport and the op_mode can know what is the
situation and bypass the useless recovery steps mentioned
above.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/ops.c

@@ -1254,7 +1254,8 @@ void iwl_mvm_nic_restart(struct iwl_mvm *mvm, bool fw_error)
 		INIT_WORK(&reprobe->work, iwl_mvm_reprobe_wk);
 		schedule_work(&reprobe->work);
 	} else if (mvm->fwrt.cur_fw_img == IWL_UCODE_REGULAR &&
-		   mvm->hw_registered) {
+		   mvm->hw_registered &&
+		   !test_bit(STATUS_TRANS_DEAD, &mvm->trans->status)) {
 		/* don't let the transport/FW power down */
 		iwl_mvm_ref(mvm, IWL_MVM_REF_UCODE_DOWN);
 
@@ -1269,7 +1270,8 @@ static void iwl_mvm_nic_error(struct iwl_op_mode *op_mode)
 {
 	struct iwl_mvm *mvm = IWL_OP_MODE_GET_MVM(op_mode);
 
-	iwl_mvm_dump_nic_error_log(mvm);
+	if (!test_bit(STATUS_TRANS_DEAD, &mvm->trans->status))
+		iwl_mvm_dump_nic_error_log(mvm);
 
 	iwl_mvm_nic_restart(mvm, true);
 }

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

@@ -480,7 +480,6 @@ struct iwl_self_init_dram {
  * @fh_mask: current unmasked fh causes
  * @hw_mask: current unmasked hw causes
  * @in_rescan: true if we have triggered a device rescan
- * @scheduled_for_removal: true if we have scheduled a device removal
  */
 struct iwl_trans_pcie {
 	struct iwl_rxq *rxq;
@@ -573,7 +572,6 @@ struct iwl_trans_pcie {
 	cpumask_t affinity_mask[IWL_MAX_RX_HW_QUEUES];
 	u16 tx_cmd_queue_size;
 	bool in_rescan;
-	bool scheduled_for_removal;
 };
 
 static inline struct iwl_trans_pcie *

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

@@ -2013,7 +2013,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,
 		if (iwlwifi_mod_params.remove_when_gone && cntrl == ~0U) {
 			struct iwl_trans_pcie_removal *removal;
 
-			if (trans_pcie->scheduled_for_removal)
+			if (test_bit(STATUS_TRANS_DEAD, &trans->status))
 				goto err;
 
 			IWL_ERR(trans, "Device gone - scheduling removal!\n");
@@ -2039,7 +2039,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,
 			 * we don't need to clear this flag, because
 			 * the trans will be freed and reallocated.
 			*/
-			trans_pcie->scheduled_for_removal = true;
+			set_bit(STATUS_TRANS_DEAD, &trans->status);
 
 			removal->pdev = to_pci_dev(trans->dev);
 			INIT_WORK(&removal->work, iwl_trans_pcie_removal_wk);
@@ -2267,8 +2267,8 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, int txq_idx)
 	u8 wr_ptr;
 
 	/* Make sure the NIC is still alive in the bus */
-	if (trans_pcie->scheduled_for_removal)
-		return -EIO;
+	if (test_bit(STATUS_TRANS_DEAD, &trans->status))
+		return -ENODEV;
 
 	if (!test_bit(txq_idx, trans_pcie->queue_used))
 		return -EINVAL;

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

@@ -1189,8 +1189,8 @@ static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans,
 	lockdep_assert_held(&trans_pcie->reg_lock);
 
 	/* Make sure the NIC is still alive in the bus */
-	if (trans_pcie->scheduled_for_removal)
-		return -EIO;
+	if (test_bit(STATUS_TRANS_DEAD, &trans->status))
+		return -ENODEV;
 
 	if (!(cmd->flags & CMD_SEND_IN_IDLE) &&
 	    !trans_pcie->ref_cmd_in_flight) {
@@ -1961,11 +1961,9 @@ static int iwl_pcie_send_hcmd_sync(struct iwl_trans *trans,
 
 int iwl_trans_pcie_send_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd)
 {
-	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
-
 	/* Make sure the NIC is still alive in the bus */
-	if (trans_pcie->scheduled_for_removal)
-		return -EIO;
+	if (test_bit(STATUS_TRANS_DEAD, &trans->status))
+		return -ENODEV;
 
 	if (!(cmd->flags & CMD_SEND_IN_RFKILL) &&
 	    test_bit(STATUS_RFKILL_OPMODE, &trans->status)) {