
< 	read_ptr = iwl_txq_get_cmd_index(txq, txq->read_ptr);
---
> 	if (txq && txq->read_ptr >= 0 && txq->read_ptr < txq->n_window)
> 		read_ptr = iwl_txq_get_cmd_index(txq, txq->read_ptr);
> 	else
> 		return;
