DESCRIPTION
The ti driver provides support for PCI Gigabit Ethernet adapters based on the Alteon Networks Tigon Gigabit Ethernet controller chip. The Tigon contains an embedded R4000 CPU, gigabit MAC, dual DMA channels and a PCI interface unit. The Tigon II contains two R4000 CPUs and other refinements. Either chip can be used in either a 32-bit or 64-bit PCI slot. Communication with the chip is achieved via PCI shared memory and bus master DMA. The Tigon I and II support hardware multicast address filtering, VLAN tag extraction and insertion, and jumbo Ethernet frames sizes up to 9000 bytes. Note that the Tigon I chipset is no longer in active production: all new adapters should come equipped with Tigon II chipsets. While the Tigon chipset supports 10, 100 and 1000Mbps speeds, support for 10 and 100Mbps speeds is only available on boards with the proper transceivers. Most adapters are only designed to work at 1000Mbps, however the driver should support those NICs that work at lower speeds as well.
Support for jumbo frames is provided via the interface MTU setting. Selecting an MTU larger than 1500 bytes with the ifconfig(8) utility configures the adapter to receive and transmit jumbo frames. Using jumbo frames can greatly improve performance for certain tasks, such as file transfers and data streaming.
Header splitting support for Tigon 2 boards (this option has no effect for the Tigon 1) can be turned on with the TI_JUMBO_HDRSPLIT option. See zero_copy(9) for more discussion on zero copy receive and header splitting.
The ti driver normally uses jumbo receive buffers allocated by the sendfile(2) buffer allocator, but can be configured to use its own private pool of jumbo buffers that are contiguous instead of buffers from the jumbo allocator, which are made up of multiple page sized chunks. To turn on private jumbos, use the TI_PRIVATE_JUMBOS option.
Support for vlans is also available using the vlan(4) mechanism. See the vlan(4) man page for more details.
The ti driver supports the following media types:
