FXP(4)                  NetBSD Kernel Interfaces Manual                 FXP(4)

NAME
     fxp -- Intel i8255x 10/100 Ethernet device driver

SYNOPSIS
     fxp* at cardbus? function ?
     fxp* at pci? dev ? function ?

DESCRIPTION
     The fxp device driver supports Ethernet interfaces based on the Intel
     i82557, i82558, i82559, and i82550 10/100 PCI Ethernet chips.

     Certain versions of the i8255x support loading microcode which implements
     a receive interrupt mitigation function, known as ``CPUSaver''.  Use of
     this option can improve performance in some situations by reducing inter-
     rupt load on the host.  This option is available on the following chip
     versions:

     o   i82558 step A4 (rev 4)
     o   i82558 step B0 (rev 5)
     o   i82559 step A0 (rev 8)
     o   i82559S step A (rev 9)
     o   i82550 (rev 12)
     o   i82550 step C (rev 13)

     This option is enabled by setting the ``link0'' option with ifconfig(8).

     Some chipset revisions can suffer from a receiver-side lockup bug which
     can be mitigated by resetting the chip every sixteen seconds without
     traffic.  Since the probe for affected chipsets generates false positives
     and the workaround can cause momentary loss of responsiveness, particu-
     larly noticeable when playing audio, the workaround is not enabled by
     default.  The boot messages will indicate if any interface may have this
     issue.  The workaround is enabled by setting the ``link1'' option with
     ifconfig(8).

HARDWARE
     Cards supported by the fxp driver include:

     o   Intel EtherExpress Pro 10+
     o   Intel EtherExpress Pro 100B
     o   Intel EtherExpress Pro 100+
     o   Intel InBusiness 10/100
     o   Intel PRO/100 S

MEDIA SELECTION
     Media selection is supported via MII.  See ifmedia(4) and mii(4) for more
     information.

     EtherExpress Pro 10+ boards may use a Seeq 80c24 AutoDUPLEX(tm) media
     interface.  Boards with these chips do not support media selection, as
     the 80c24 has no programming interface, and no way to read link status.
     These boards claim a media of "manual" since they self-configure based on
     the configuration of the link partner (hub or switch).

DIAGNOSTICS
     fxp0: WARNING: SCB timed out!  The driver timed out waiting for the
     chip's command interface to become ready.

     fxp0: too many segments, aborting  The driver encountered a packet that
     included too many DMA segments, and was not able to allocate a new buffer
     to transmit the packet from.  The packet has been dropped.

     fxp0: too many segments, retrying  The driver encountered a packet that
     included too many DMA segments, and allocated a new buffer to transmit
     the packet from.

     fxp0: can't load mbuf chain, error = %d  The driver was unable to load a
     transmit DMA map, and has reported the errno value.

     fxp0: device timeout  The device failed to generate a transmit complete
     interrupt for the last packet transmitted.  The device has been reset.

     fxp0: can't load rx buffer, error = %d  The driver was unable to load the
     DMA map for a receive buffer, and has reported the errno value.  This
     error is currently fatal, and will panic the system.

     fxp0: fxp_mdi_read: timed out  The MDIO failed to become ready during an
     MII read operation.

     fxp0: fxp_mdi_write: timed out  The MDIO failed to become ready during an
     MII write operation.

     fxp0: May need receiver lock-up workaround  The interface may need to be
     periodically reset to workaround a receiver lock-up bug.

SEE ALSO
     cardbus(4), ifmedia(4), intro(4), mii(4), pci(4), ifconfig(8)

NetBSD 5.0_STABLE              October 15, 2005              NetBSD 5.0_STABLE
