Ubuntu Manpage: ath — Atheros IEEE 802.11 wireless network driver

Provided by: freebsd-manpages_9.2+1-1_all

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, and AR5416 programming APIs. These APIs are used by a wide variety of chips; most all chips with
a PCI and/or CardBus interface are supported.

Supported features include 802.11 and 802.3 frames, power management, BSS, IBSS, MBSS, 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-class devices are capable of 802.11n operation but are supported only in
legacy modes (802.11a, 11b, 11g). 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
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 and AR5416 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 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 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 and PCI 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.

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

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

       The driver does not fully enable power-save operation of the chip in station mode; consequently power use
       is suboptimal (e.g. on a laptop).

       WPA is not supported for 5210 parts.

Debian                                           August 28, 2011                                          ATH(4)