iwlwifi: avoid read/write operations if the bus is dead

Recovery takes too much time if the bus is dead (each timeout
is 2000ms, etc.).
Explicitly skip fw dump in this case, as it will result in
garbage data (and might take signifcant time)
Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-trans.h

@@ -409,6 +409,7 @@ enum iwl_d3_status {
  * @STATUS_TRANS_GOING_IDLE: shutting down the trans, only special commands
  *	are sent
  * @STATUS_TRANS_IDLE: the trans is idle - general commands are not to be sent
+ * @STATUS_TRANS_DEAD: trans is dead - avoid any read/write operation
  */
 enum iwl_trans_status {
 	STATUS_SYNC_HCMD_ACTIVE,
@@ -419,6 +420,7 @@ enum iwl_trans_status {
 	STATUS_FW_ERROR,
 	STATUS_TRANS_GOING_IDLE,
 	STATUS_TRANS_IDLE,
+	STATUS_TRANS_DEAD,
 };
 
 /**

drivers/net/wireless/iwlwifi/mvm/mac80211.c

@@ -1137,6 +1137,12 @@ void iwl_mvm_fw_error_dump(struct iwl_mvm *mvm)
 
 	lockdep_assert_held(&mvm->mutex);
 
+	/* there's no point in fw dump if the bus is dead */
+	if (test_bit(STATUS_TRANS_DEAD, &mvm->trans->status)) {
+		IWL_ERR(mvm, "Skip fw error dump since bus is dead\n");
+		return;
+	}
+
 	if (mvm->fw_dump_trig &&
 	    mvm->fw_dump_trig->mode & IWL_FW_DBG_TRIGGER_MONITOR_ONLY)
 		monitor_dump_only = true;