3c575_cb is the low-level Card Services driver for the 3Com
3c575 EtherLink XL CardBus series ethernet adapters. When this driver
is attached to a card, it allocates the next available ethernet device
(eth0..eth#). This information for this card will be
reported in the kernel log file, and the device name passed on to
cardmgr(8).
The driver uses the N-Way autonegotiating transceiver to negotiate the
speed and duplex of the network link. If the link partner does not
support negotiation only the link speed is detected.
If the on-card EEPROM is programmed for a full-duplex (FD) link, only
FD media types are advertised and the link is assumed to be full-duplex.
PARAMETERS
rx_copybreak=n
Set the breakpoint for copying incoming frames into reduced-sized
packet buffers. The default value of 200 bytes is reasonable for most
systems.
max_interrupt_work=n
This option selects the maximum amount of work handled during each
interrupt. Each received packet counts as one unit of work, as does
updating statistics counters and handling errors. The default value
of 32 should only need to be increased on very slow machines. An
occasional "too much work in interrupt" message is not a problem.
use_hw_csums=n
Controls use of an adapter's on-board TCP/IP checksum verification for
incoming packets. This is on by default; setting to 0 disables
hardware checksums. It may be useful to disable hardware checksums if
it is suspected that something is corrupting data on its way from the
card to the CPU.
down_poll_rate=n
For Cyclone and Tornado chipsets, this is the rate at which the card
polls the transmit ring for new packets. The value is in units of 320
ns; a value of 0 disables polling. The default is 20 (6.4 us), and
the maximum allowed value is 127. Polling is more efficient but can
consume a significant amount of PCI bus bandwidth.
This flag can be used to control the transceiver's auto polarity
detection capability. Some Cisco Catalyst switches are known to
interact badly with this feature in 10baseT mode. It defaults to 1
(enabled).
