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ath(4)

NAME

     ath -- Atheros IEEE 802.11 wireless network driver

SYNOPSIS

     device ath
     device ath_hal
     device wlan

DESCRIPTION

     The ath driver provides support for wireless network adapters based on
     the Atheros AR5210, AR5211, and AR5212 chips.  Chip-specific support is
     provided by the Atheros Hardware Access Layer (HAL), that is packaged
     separately.

     Supported features include 802.11 and 802.3 frames, power management,
     BSS, IBSS, and host-based access point operation modes.  All host/device
     interaction is via DMA.

     The ath driver encapsulates all IP and ARP traffic as 802.11 frames, how-
     ever it can receive either 802.11 or 802.3 frames.  Transmit speed and
     operating mode is selectable and depends on the specific chipset.
     AR5210-based devices support 802.11a operation with transmit speeds of 6
     Mbps, 9 Mbps, 12 Mbps, 18 Mbps, 24 Mbps, 36 Mbps, 48 Mbps, and 54 Mbps.
     AR5211-based devices support 802.11a and 802.11b operation with transmit
     speeds as above for 802.11a operation and 1Mbps, 2Mbps, 5.5 Mbps and
     11Mbps for 802.11b operation.  AR5212-based devices support 802.11a,
     802.11b, and 802.11g operation with transmit speeds appropriate to each.
     All chips also support an Atheros Turbo Mode (TM) that operates in the
     802.11a frequency range with 2x the transmit speeds.  (This mode is, how-
     ever, only interoperable with other Atheros-based devices.)  The actual
     transmit speed used is dependent on signal quality and the ``rate
     control'' algorithm employed by the driver.  All chips support WEP
     encryption.  AR5211 and AR5212 support the AES, TKIP, and Michael crypto-
     graphic operations required for WPA but at this time the driver does not
     support them.  To enable encryption, use ifconfig(8) as shown below.

     By default, the ath driver configures the card for BSS operation (aka in-
     frastructure mode).  This mode requires the use of an access point (base
     station).

     The ath driver also supports the standard IBSS point-to-point mode where
     stations can communicate amongst themselves without the aid of an access
     point.

     The driver may also be configured to operate in hostap mode.  In this
     mode a host may function as an access point (base station).  Access
     points are different than operating in IBSS mode.	They operate in BSS
     mode.  They allow for easier roaming and bridge all Ethernet traffic such
     that machines connected via an access point appear to be on the local
     Ethernet segment.

     For more information on configuring this device, see ifconfig(8).

     Devices supported by the ath driver come in either Cardbus or mini-PCI
     packages.	Wireless cards in Cardbus slots may be inserted and ejected on
     the fly.

     D-Link DWL-AG520	  AR5212    PCI        a/b/g
     D-Link DWL-AG650	  AR5212    CardBus    a/b/g
     D-Link DWL-G520B	  AR5212    PCI        b/g
     D-Link DWL-G650B	  AR5212    CardBus    b/g
     Elecom LD-WL54AG	  AR5212    Cardbus    a/b/g
     Elecom LD-WL54	  AR5211    Cardbus    a
     Fujitsu E5454	  AR5212    Cardbus    a/b/g
     Fujitsu FMV-JW481	  AR5212    Cardbus    a/b/g
     Fujitsu E5454	  AR5212    Cardbus    a/b/g
     HP NC4000		  AR5212    PCI        a/b/g
     I/O Data WN-AB	  AR5212    CardBus    a/b
     I/O Data WN-AG	  AR5212    CardBus    a/b/g
     I/O Data WN-A54	  AR5212    CardBus    a
     Linksys WMP55AG	  AR5212    PCI        a/b/g
     Linksys WPC51AB	  AR5211    CardBus    a/b
     Linksys WPC55AG	  AR5212    CardBus    a/b/g
     NEC PA-WL/54AG	  AR5212    CardBus    a/b/g
     Netgear WAG311	  AR5212    PCI        a/b/g
     Netgear WAB501	  AR5211    CardBus    a/b
     Netgear WAG511	  AR5212    CardBus    a/b/g
     Netgear WG311	  AR5212    PCI        b/g
     Netgear WG311T	  AR5212    PCI        b/g
     Netgear WG511T	  AR5212    CardBus    b/g
     Orinoco 8480	  AR5212    CardBus    a/b/g
     Orinoco 8470WD	  AR5212    CardBus    a/b/g
     Proxim Skyline 4030  AR5210    CardBus    a
     Proxim Skyline 4032  AR5210    PCI        a
     Samsung SWL-5200N	  AR5212    CardBus    a/b/g
     SMC SMC2536W-AG	  AR5212    CardBus a/b/g
     SMC SMC2735W	  AR5210    CardBus    a
     Sony PCWA-C700	  AR5212    Cardbus    a/b
     Sony PCWA-C300S	  AR5212    Cardbus    b/g
     Sony PCWA-C500	  AR5210    Cardbus    a
     3Com 3CRPAG175	  AR5212    CardBus    a/b/g

     An up to date list can be found at
     http://customerproducts.atheros.com/customerproducts.

EXAMPLES

     Join an existing BSS network (ie: connect to an access point):

	   ifconfig ath0 inet 192.168.0.20 netmask 0xffffff00

     Join a specific BSS network with network name ``my_net'':

	   ifconfig ath0 inet 192.168.0.20 netmask 0xffffff00 ssid my_net

     Join a specific BSS network with WEP encryption:

	   ifconfig ath0 inet 192.168.0.20 netmask 0xffffff00 ssid my_net \
		   wepmode on wepkey 0x8736639624

     Join/create an 802.11b IBSS network with network name ``my_net'':

	   ifconfig ath0 inet 192.168.0.22 netmask 0xffffff00 ssid my_net \
		   mode 11b mediaopt adhoc

     Create an 802.11g host-based access point:

     Create a host-based wireless bridge to fxp0:

	   Add BRIDGE to the kernel config.
	   ifconfig ath0 inet up ssid my_ap media DS/11Mbps mediaopt hostap
	   sysctl net.link.ether.bridge.enable=1
	   sysctl net.link.ether.bridge.config="ath0 fxp0"
	   sysctl net.inet.ip.check_interface=0

     This will give you the same functionality as an access point.

DIAGNOSTICS

     ath%d: unable to attach hardware; HAL status %u  The Atheros Hardware
     Access Layer was unable to configure the hardware as requested.  The sta-
     tus code is explained in the HAL include file sys/contrib/dev/ath/ah.h.

     ath%d: failed to allocate descriptors: %d	The driver was unable to allo-
     cate contiguous memory for the transmit and receive descriptors.  This
     usually indicates system memory is scarce and/or fragmented.

     ath%d: unable to setup a data xmit queue!	The request to the HAL to set
     up the transmit queue for normal data frames failed.  This should not
     happen.

     ath%d: unable to setup a beacon xmit queue!  The request to the HAL to
     set up the transmit queue for 802.11 beacon frames frames failed.	This
     should not happen.

     ath%d: 802.11 address: %s	The MAC address programmed in the EEPROM is
     displayed.

     ath%d: hardware error; resetting  An unrecoverable error in the hardware
     occurred.	Errors of this sort include unrecoverable DMA errors.  The
     driver will reset the hardware and continue.

     ath%d: rx FIFO overrun; resetting	The receive FIFO in the hardware over-
     flowed before the data could be transferred to the host.  This typically
     occurs because the hardware ran short of receive descriptors and had no
     place to transfer received data.  The driver will reset the hardware and
     continue.

     ath%d: unable to reset hardware; hal status %u  The Atheros Hardware
     Access Layer was unable to reset the hardware as requested.  The status
     code is explained in the HAL include file sys/contrib/dev/ath/ah.h.  This
     should not happen.

     ath%d: unable to start recv logic	The driver was unable to restart frame
     reception.  This should not happen.

     ath%d: device timeout  A frame dispatched to the hardware for transmis-
     sion did not complete in time.  The driver will reset the hardware and
     continue.	This should not happen.

     ath%d: bogus xmit rate 0x%x  An invalid transmit rate was specified for
     an outgoing frame.  The frame is discarded.  This should not happen.

     ath%d: ath_chan_set: unable to reset channel %u (%u Mhz)  The Atheros
     Hardware Access Layer was unable to reset the hardware when switching

     ath%d: %s: %dM -> %dM (%d ok, %d err, %d retr)  The driver's rate control
     algorithm changed the current rate for transmitting frames.  This message
     is temporarily enabled for normal use to help in diagnosing and improving
     the rate control algorithm.  The message indicates the new and old trans-
     mit rates and the statistics it used to decide on this change.

     ath%d: failed to enable memory mapping  The driver was unable to enable
     memory-mapped I/O to the PCI device registers.  This should not happen.

     ath%d: failed to enable bus mastering  The driver was unable to enable
     the device as a PCI bus master for doing DMA.  This should not happen.

     ath%d: cannot map register space  The driver was unable to map the device
     registers into the host address space.  This should not happen.

     ath%d: could not map interrupt  The driver was unable to allocate an IRQ
     for the device interrupt.	This should not happen.

     ath%d: could not establish interrupt  The driver was unable to install
     the device interrupt handler.  This should not happen.

SEE ALSO

     an(4), arp(4), ath_hal(4), card(4), netintro(4), pcic(4), wi(4), wlan(4),
     ifconfig(8), wicontrol(8)

HISTORY

     The ath device driver first appeared in FreeBSD 5.2.

CAVEATS

     Different regulatory domains have different default channels for adhoc
     mode.  See ifconfig(8) for information on how to change the channel.  See
     wicontrol(8) for information on different regulatory domains.  Different
     regulatory domains may not be able to communicate with each other with
     802.11a as different regulatory domains do not necessarily have overlap-
     ping channels.

     Revision A1 of the D-LINK DWL-G520 and DWL-G650 are based on an Intersil
     PrismGT chip and are not supported by this driver.

BUGS

     Performance in lossy environments is suboptimal.  The algorithm used to
     select the rate for transmitted packets is very simplistic.  There is no
     software retransmit; only hardware retransmit is used.  Contributors are
     encouraged to replace the existing rate control algorithm with a better
     one (hint: all the information needed is available to the driver).

     The driver does not fully enable power-save operation of the chip; conse-
     quently power use is suboptimal.

FreeBSD 5.4		       December 29, 2004		   FreeBSD 5.4

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