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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_pci
             device ath_hal
             options AH_SUPPORT_AR5416
             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"
             if_ath_pci_load="YES"

DESCRIPTION

       The  ath  driver  provides  support  for  wireless  network adapters based on the Atheros AR5210, AR5211,
       AR5212, AR5416 and AR9300 programming APIs.  These APIs are used by a wide variety  of  chips;  most  all
       chips with a PCI, PCIe and/or CardBus interface are supported.

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

       Please  note  that  from  FreeBSD-9.0,  the  ath driver does not include the PCI/PCIe bus glue.  The same
       driver supports multiple underlying bus types, including PCI/PCIe, but also embedded (AHB) and USB in the
       future.

       To enable use for PCI/PCIe systems, see the ath_pci(4) driver.  For embedded systems which use the AHB to
       connect the wireless MAC, see the ath_ahb(4) driver.

       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.  AR5416 and later class devices are capable of 802.11n operation.  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.)  AR5212-based and AR5416-based  devices  also  support  half-  (10MHz)  and
       quarter-width  (5MHz)  channels.   The  actual transmit speed used is dependent on signal quality and the
       “rate control” algorithm employed by the driver.  All chips support WEP encryption.  AR5212,  AR5416  and
       later  parts  have  hardware support for the AES-CCM, TKIP, and Michael cryptographic operations required
       for WPA.  To enable encryption, use ifconfig(8) as shown below.

       The driver supports station, adhoc, adhoc-demo, hostap, mesh, wds, and monitor mode operation.   Multiple
       hostap  virtual interfaces may be configured for simultaneous use on cards that use a 5212 or later part.
       When multiple interfaces are configured each may have a separate mac address that is  formed  by  setting
       the  U/L bits in the mac address assigned to the underlying device.  Any number of wds virtual interfaces
       may be configured together with hostap interfaces.  Multiple station interfaces may be operated  together
       with  hostap  interfaces to construct a wireless repeater device.  The driver also support tdma operation
       when compiled with options IEEE80211_SUPPORT_TDMA (which also enables the required 802.11 support).   For
       more information on configuring this device, see ifconfig(8).

       Devices  supported  by  the  ath  driver  come  in Cardbus, ExpressCard, Mini-PCI and Mini-PCIe packages.
       Wireless cards in Cardbus and ExpressCard slots may be inserted and ejected on the fly.

HARDWARE

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

EXAMPLES

       Join a specific BSS network with WEP encryption:

             ifconfig wlan0 create wlandev ath0
             ifconfig wlan0 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 wlan0 create wlandev ath0 wlanmode adhoc
             ifconfig wlan0 inet 192.168.0.22 netmask 0xffffff00 ssid my_net \
                     mode 11b

       Create an 802.11g host-based access point:

             ifconfig wlan0 create wlandev ath0 wlanmode hostap
             ifconfig wlan0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap \
                     mode 11g

       Create an 802.11a mesh station:

             ifconfig wlan0 create wlandev ath0 wlanmode mesh
             ifconfig wlan0 meshid my_mesh mode 11a inet 192.168.0.10/24

       Create two virtual 802.11a host-based access points, one with WEP enabled and one with no  security,  and
       bridge them to the fxp0 (wired) device:

             ifconfig wlan0 create wlandev ath0 wlanmode hostap \
                     ssid paying-customers wepmode on wepkey 0x1234567890 \
                     mode 11a up
             ifconfig wlan1 create wlandev ath0 wlanmode hostap bssid \
                     ssid freeloaders up
             ifconfig bridge0 create addm wlan0 addm wlan1 addm fxp0 up

       Create a master node in a two slot TDMA BSS configured to use 2.5 millisecond slots.

             ifconfig wlan0 create wlandev ath0 wlanmode tdma \
                     ssid tdma-test tmdaslot 0 tdmaslotlen 2500 \
                     channel 36 up

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/dev/ath/ath_hal/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 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/dev/ath/ath_hal/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: 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

       ath_hal(4),   cardbus(4),   intro(4),   pcic(4),   wlan(4),   wlan_ccmp(4),   wlan_tkip(4),  wlan_wep(4),
       wlan_xauth(4), hostapd(8), ifconfig(8), wpa_supplicant(8)

HISTORY

       The ath device driver first appeared in FreeBSD 5.2.

CAVEATS

       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

       The driver does supports optional station mode power-save operation.

       The  AR5210 can only do WEP in hardware; consequently hardware assisted WEP is disabled in order to allow
       software implementations of TKIP and CCMP to function.  Hardware WEP can be re-enabled by  modifying  the
       driver.

Debian                                            June 16, 2020                                           ATH(4)