hi , 

I try to driver a nic ('RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet Controller 8168') ,  

when I use 'rte_eth_dev_configure' which tx port set to 0, then  running  'rte_eth_dev_start' may crash !

because at this time 'tx_queues' is null, but still access with 'dev->data->tx_queue' at r8169_rxtx.c:1102. 

detail stack info picture in the attachment.