ATH(4) MidnightBSD Kernel Interfaces Manual ATH(4)

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 following cards are among those supported by the ath driver:

Card Chip Bus Standard
Aztech WL830PC AR5212 CardBus b/g
Cisco AIR-CB21AG AR5115 Cardbus a/b/g
Cisco AIR-PI21AG AR5115 PCI a/b/g
D-Link DWL-A650 AR5210 CardBus a
D-Link DWL-AB650 AR5211 CardBus a/b
D-Link DWL-A520 AR5210 PCI a
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 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:

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

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

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 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.

MidnightBSD 0.3 September 5, 2005 MidnightBSD 0.3