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.
There are several PCI boards available from both Alteon and other vendors that use the Tigon chipset under OEM contract. The ti driver has been tested with the following Tigon-based adapters:
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The Alteon AceNIC V gigabit (1000BASE-SX and 1000BASE-T variants) Ethernet adapter
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The 3Com 3c985-SX gigabit Ethernet adapter
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The Netgear GA620 gigabit (1000BASE-SX and 1000BASE-T variants) Ethernet adapter
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The Digital EtherWORKS 1000SX PCI Gigabit Adapter (DEGPA)
The following should also be supported but have not yet been tested:
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Silicon Graphics PCI gigabit Ethernet adapter
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.
The ti driver supports the following media types:
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autoselect
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Enable autoselection of the media type and options.
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10baseT/UTP
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Set 10Mbps operation. The mediaopt option can also be used to select either full-duplex or half-duplex modes.
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100baseTX
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Set 100Mbps (fast Ethernet) operation. The mediaopt option can also be used to select either full-duplex or half-duplex modes.
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1000baseSX
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Set 1000Mbps (gigabit Ethernet over multimode fiber) operation. Only full full-duplex mode is supported at this speed.
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1000baseT
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Set 1000Mbps (gigabit Ethernet over twisted pair) operation. Only full full-duplex mode is supported at this speed.
The ti driver supports the following media options:
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full-duplex
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Force full duplex operation.
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half-duplex
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Force half duplex operation.
The Alteon Tigon and Tigon II support IPv4/TCP/UDP checksumming in hardware. The ti supports this feature of the chip's firmware. See ifconfig(8) for information on how to enable this feature.
For more information on configuring this device, see ifconfig(8).
BUGS
The driver currently tries to access some on-board memory transparently. This mapping (BUS_SPACE_MAP_LINEAR) fails on systems where the corresponding PCI memory range is located in "sparse" space only.
This driver currently does not work on big-endian systems.