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 sepa

rately.

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 appro

priate to each.
Most chips also support an Atheros Turbo Mode (TM) that op

erates 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 quali

ty 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 en

able encryption,
use ifconfig(8) as shown below.

By default, the ath driver configures the card for BSS oper

ation (aka
infrastructure mode). This mode requires the use of an ac

cess 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 op

erate 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 ifcon

fig(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 me

diaopt 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 re

quested. 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 descrip

tors. 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 er

rors. 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 un

able 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 un

able 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 hap

pen.

ath%d: could not map interrupt The driver was unable to al

locate 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 do

mains. 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 oper

ating 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.

BSD September 5, 2005

BSD