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NAME

     ath - Atheros IEEE 802.11 wireless network driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your
     kernel configuration file:

           device ath
           device ath_hal
           device ath_rate_sample
           device wlan

     Alternatively, to load the driver as a module at boot time, place the
     following line in loader.conf(5):

           if_ath_load="YES"

DESCRIPTION

     The ath driver provides support for wireless network adapters based on
     the Atheros AR5210, AR5211, and AR5212 programming APIs.  These APIs are
     used by a wide variety of chips; all chips with a PCI and/or CardBus
     interface are supported.  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,
     however 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.
     Most chips also support an Atheros Turbo Mode (TM) that operates in the
     5Ghz frequency range with 2x the transmit speeds.  Some chips also
     support Turbo mode in the 2.4Ghz range with 802.11g though this support
     is not presently available due to regulatory requirements.  (Note that
     Turbo modes are, however, 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.  The AR5212 has hardware support for the AES-CCM,
     TKIP, and Michael cryptographic operations required for WPA.  To enable
     encryption, use ifconfig(8) as shown below.

     By default, the ath driver configures the card for BSS operation (aka
     infrastructure 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.

HARDWARE

     The ath driver supports all Atheros Cardbus or PCI cards, except those
     that are based on the AR5005VL chipset.

     A list of cards that are supported can be found at
     http://customerproducts.atheros.com/customerproducts/default.asp.

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:

           ifconfig ath0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap \
                   mode 11g mediaopt hostap

     Create an 802.11a host-based access point with WEP enabled:

           ifconfig ath0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap \
                   wepmode on wepkey 0x1234567890 mode 11a mediaopt hostap

     Create a host-based wireless bridge to fxp0:

           ifconfig ath0 inet up ssid my_ap media DS/11Mbps mediaopt hostap
           sysctl net.inet.ip.check_interface=0
           ifconfig bridge0 create
           ifconfig bridge0 addm ath0 addm fxp0 up

     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
     status 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
     allocate 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
     overflowed 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
     transmission 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
     channels during scanning.  This should not happen.

     ath%d: unable to allocate channel table  The driver was unable to
     allocate memory for the table used to hold the set of available channels.

     ath%d: unable to collect channel list from hal  A problem occurred while
     querying the HAL to find the set of available channels for the device.
     This should not happen.

     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

     altq(4), an(4), arp(4), ath_hal(4), netintro(4), pcic(4), wi(4), wlan(4),
     ifconfig(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.
     Different regulatory domains may not be able to communicate with each
     other with 802.11a as different regulatory domains do not necessarily
     have overlapping 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

     There is no software retransmit; only hardware retransmit is used.

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

     The driver honors the regulatory domain programmed into the EEPROM of a
     device and does not support overriding this setting.  This is done to
     insure compliance with local regulatory agencies when operating as an
     access point.  Unfortunately this also means that devices purchased for
     use in one locale may not be usable in another.  Changes are planned to
     remove this restriction when operating in station mode.

     WPA is not supported for 5210 parts.

     Atheros’ SuperG functionality is not supported.