ATH(4)

ATH(4) | NetBSD Kernel Interfaces Manual | ATH(4)

# NAME

ath — Atheros IEEE 802.11 driver

# SYNOPSIS

ath* at pci? dev ? function ?
ath* at cardbus? function ?

# DESCRIPTION

The ath driver provides support for wireless network adapters based on the Atheros AR2413, AR2417, AR5210, AR5211, AR5212, AR5213, AR5413, AR5416, AR5424, AR9160, AR9280, and AR9285 chips. Chip-specific support is provided by the Atheros Hardware Access Layer (HAL).

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 depending on your hardware.

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 and AR5213-based devices support 802.11a, 802.11b, and 802.11g operation with transmit speeds appropriate to each.

All chips also support an Atheros Turbo Mode (TM) that operates in the 802.11a frequency range with 2x the transmit speeds. (This mode is, 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. AR5211 and AR5212 support the AES, TKIP, and Michael cryptographic operations required for WPA but at this time the driver does not support them. To enable encryption, use ifconfig(8).

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.

The mode of operation is chosen by specifying the appropriate mediaopt value to ifconfig. The -m flag to ifconfig will list the available options.

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.

The following cards are among those supported by the ath driver:

Card | Chip | Bus | Standard
3Com 3CRPAG175 | AR5212 | CardBus | a/b/g
Airlink AWLH4030 | AR5212 | PCI | b/g
Aztech WL830PC | AR5212 | CardBus | b/g
Belkin F6D3000 | AR5212 | PCI | a/b/g
D-Link DWL-A520 | AR5210 | PCI | a
D-Link DWL-A650 | AR5210 | CardBus | a
D-Link DWL-AB650 | AR5211 | CardBus | a/b
D-Link DWL-AG520 | AR5212 | PCI | a/b/g
D-Link DWL-AG650 | AR5212 | CardBus | a/b/g
D-Link DWL-AG660 | AR521? | CardBus | a/b/g
D-Link DWL-G520 | AR5212 | PCI | b/g
D-Link DWL-G650B | AR5212 | CardBus | b/g
Elecom LD-WL54 | AR5211 | CardBus | a
Elecom LD-WL54AG | AR5212 | CardBus | a/b/g
Fujitsu E5454 | AR5212 | CardBus | a/b/g
Fujitsu E5454 | AR5212 | CardBus | a/b/g
Fujitsu FMV-JW481 | AR5212 | CardBus | a/b/g
HP NC4000 | AR5212 | PCI | a/b/g
I/O Data WN-A54 | AR5212 | CardBus | a
I/O Data WN-AB | AR5212 | CardBus | a/b
I/O Data WN-AG | AR5212 | CardBus | a/b/g
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 WAB501 | AR5211 | CardBus | a/b
Netgear WAG311 | AR5212 | PCI | a/b/g
Netgear WAG511 | AR5212 | CardBus | a/b/g
Netgear WG311 | AR5212 | PCI | b/g
Netgear WG511T | AR5212 | CardBus | b/g
Orinoco 8470WD | AR5212 | CardBus | a/b/g
Orinoco 8480 | AR5212 | CardBus | a/b/g
Planex GW-NS54AG | 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 SMC2735W | AR5210 | CardBus | a
Sony PCWA-C300S | AR5212 | CardBus | b/g
Sony PCWA-C500 | AR5210 | CardBus | a
Sony PCWA-C700 | AR5212 | CardBus | a/b
Ubiquiti SRC | AR5213 | CardBus | a/b/g

An up to date list can be found at http://customerproducts.atheros.com/customerproducts.

# 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 contrib/sys/dev/ic/athhal.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 setup 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 setup 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 contrib/sys/dev/ic/athhal.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: %s: %dM -> %dM (%d ok, %d err, %d retr)
  The driver's rate control algorithm changed the current rate for transmitting frames. This message is temporarily enabled for normal use to help in diagnosing and improving the rate control algorithm. The message indicates the new and old transmit rates and the statistics it used to decide on this change.
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

arp(4), cardbus(4), ifmedia(4), netintro(4), pci(4), ifconfig(8)

# HISTORY

The ath device driver first appeared in FreeBSD 5.2. It was ported to NetBSD 2.0.

# AUTHORS

The ath driver was originally written by Sam Leffler, and was ported to NetBSD by David Young.

# CAVEATS

Different regulatory domains have different default channels for adhoc mode. See ifconfig(8) for information on how to change the channel. 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.

Revision v2 of the Netgear WG311 is based on a Texas Instruments ACX111 and is not supported by this driver.

Revision v3 of the Netgear WG311 is based on a Marvell Libertas 88W8335 and is not supported by this driver.

# BUGS

Performance in lossy environments is suboptimal. The algorithm used to select the rate for transmitted packets is very simplistic. There is no software retransmit; only hardware retransmit is used. Contributors are encouraged to replace the existing rate control algorithm with a better one (hint: all the information needed is available to the driver).

The driver does not fully enable power-save operation of the chip; consequently power use is suboptimal.

February 21, 2011 | NetBSD 5.99