3C575_CB(4)						     Kernel Interfaces Manual						       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_interrupt_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 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  dis-
	      ables  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 effi-
	      cient 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.

SEE ALSO

       cardmgr(8), pcmcia(5).

pcmcia-cs							2001/06/22 01:12:38						       3C575_CB(4)