vte4

Usage

Overview

The vte device driver provides support for RDC R6040 Fast Ethernet controller which is commonly found on Vortex86 System On a Chip (SoC).

The RDC R6040 has integrated 10/100 PHY for 10/100Mbps support in full or half-duplex. The controller supports interrupt moderation mechanism, a 64-bit multicast hash filter, VLAN over-size frame and four station addresses. The vte device driver uses three station addresses out of four as perfect multicast filter.

The vte driver supports the following media types:

autoselect

Enable autoselection of the media type and options. The user can manually override the autoselected mode by adding media options to rc.conf(5).

10baseT/UTP

Set 10Mbps operation.

100baseTX

Set 100Mbps (Fast Ethernet) operation.

The vte driver supports the following media options:

full-duplex

Force full duplex operation.

half-duplex

Force half duplex operation.

For more information on configuring this device, see ifconfig(8).

Hardware

The vte device driver provides support for the following Ethernet controllers:

• DM&P Vortex86 RDC R6040 Fast Ethernet controller

Loader tunables

Tunables can be set at the loader(8) prompt before booting the kernel or stored in loader.conf(5).

hw.vte.tx_deep_copy

The RDC R6040 controller has no auto-padding support for short frames and the controller's DMA engine does not have capability to handle multiple buffers for a TX frame such that driver has to create a single contiguous TX buffer. This hardware limitation leads to poor TX performance since most of CPU cycles are wasted on both de-fragmenting mbuf chains and padding. This tunable enables deep copy operation for TX frames such that driver will spend less CPU cycles in de-fragmentation with the cost of extra TX buffer memory. The default value is 1 to use deep copy.

Sysctl variables

The following variables are available as both sysctl(8) variables and loader(8) tunables:

dev.vte.%d.rx_mod

Maximum number of packets to fire RX completion interrupt. The accepted range is 0 to 15, the default is 15.

dev.vte.%d.tx_mod

Maximum number of packets to fire TX completion interrupt. The accepted range is 0 to 15, the default is 15.

dev.vte.%d.stats

Show hardware MAC statistics maintained in driver.