ath — Atheros IEEE 802.11 wireless network 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)

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.

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 optionsIEEE80211_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.

Diagnostics

ath%d:unabletoattachhardware;HALstatus%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:failedtoallocatedescriptors:%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:unabletosetupadataxmitqueue! The request to the HAL to set up the transmit queue for normal
data frames failed. This should not happen.

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

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

ath%d:hardwareerror;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:rxFIFOoverrun;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:unabletoresethardware;halstatus%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:unabletostartrecvlogic The driver was unable to restart frame reception. This should not
happen.

ath%d:devicetimeout 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:bogusxmitrate0x%x An invalid transmit rate was specified for an outgoing frame. The frame is
discarded. This should not happen.

ath%d:ath_chan_set:unabletoresetchannel%u(%uMHz) The Atheros Hardware Access Layer was unable to
reset the hardware when switching channels during scanning. This should not happen.

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

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

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

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

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

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

Hardware

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

History

       The ath device driver first appeared in FreeBSD 5.2.

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:

             deviceathdeviceath_pcideviceath_haloptionsAH_SUPPORT_AR5416deviceath_rate_sampledevicewlan

       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"