3c575_cb(4)
NAME
3c575_cb - 3Com 3c575 Etherlink XL 10/100 CardBus device
driver
SYNOPSIS
insmod 3c575_cb.o [debug=n] [rx_copybreak=n] [max_inter rupt_work=n] [use_hw_csums=n] [down_poll_rate=n] [auto_polarity=n]
DESCRIPTION
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 infor
mation 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 han
dled 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 prob
lem. - use_hw_csums=n
- Controls use of an adapter's on-board TCP/IP check
sum verification for incoming packets. This is on
by default; setting to 0 disables hardware check
sums. It may be useful to disable hardware check
sums if it is suspected that something is corrupt
ing 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).
AUTHOR
This driver: Donald Becker - becker@scyld.com
Linux PC Card control software: David Hinds dahinds@users.sourceforge.net et al.