1.\"- 2.\" Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 3.\" All rights reserved. 4.\"" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer, 10.\" without modification. 11.\" 2. Redistributions in binary form must reproduce at minimum a disclaimer 12.\" similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any 13.\" redistribution must be conditioned upon including a substantially 14.\" similar Disclaimer requirement for further binary redistribution. 15.\" 3. Neither the names of the above-listed copyright holders nor the names 16.\" of any contributors may be used to endorse or promote products derived 17.\" from this software without specific prior written permission. 18.\" 19.\" NO WARRANTY 20.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22.\" LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 23.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 24.\" THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 25.\" OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 28.\" IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 30.\" THE POSSIBILITY OF SUCH DAMAGES. 31.\" 32.\" $FreeBSD$ 33.\"/ 34.Dd July 13, 2003 35.Dt ATH 4 36.Os 37.Sh NAME 38.Nm ath 39.Nd "Atheros IEEE 802.11 driver" 40.Sh SYNOPSIS 41.Cd "device ath" 42.Cd "device ath_hal" 43.Cd "device wlan" 44.Sh DESCRIPTION 45The 46.Nm 47driver provides support for wireless network adapters based on 48the Atheros AR5210, AR5211, and AR5212 chips. 49Chip-specific support is provided by the Atheros Hardware Access Layer 50(HAL), that is packaged separately. 51.Pp 52Supported features include 802.11 and 802.3 frames, power management, BSS, 53IBSS, and host-based access point operation modes. 54All host/device interaction is via DMA. 55.Pp 56The 57.Nm 58driver encapsulates all IP and ARP traffic as 802.11 frames, however 59it can receive either 802.11 or 802.3 frames. 60Transmit speed and operating mode is selectable 61depending on your hardware. 62AR5210-based devices support 802.11a operation with trasmit speeds 63of 6 Mbps, 9 Mbps, 12 Mbps, 18 Mbps, 24 Mbps, 36 Mbps, 48 Mbps, and 54 Mbps. 64AR5211-based devices support 802.11a and 802.11b operation with transmit 65speeds as above for 802.11a operation and 661Mbps, 2Mbps, 5.5 Mbps and 11Mbps for 802.11b operation. 67AR5212-based devices support 802.11a, 802.11b, and 802.11g operation 68with transmit speeds appropriate to each. 69All chips also support an Atheros Turbo Mode (TM) that operates in the 802.11a frequency range with 2x the transmit speeds. 70(This mode is, however, only interoperable with other Atheros-based devices.) 71The actual transmit speed used is dependent on signal quality and the 72``rate control'' algorithm employed by the driver. 73All chips support WEP encryption. 74AR5211 and AR5212 support the AES, TKIP, and Michael cryptographic 75operations required for WPA but at this time the driver does not support them. 76To enable encryption, use 77.Xr ifconfig 8 78as shown below. 79.Pp 80By default, the 81.Nm 82driver configures the card for BSS operation (aka infrastructure 83mode). 84This mode requires the use of an access point (base station). 85.Pp 86The 87.Nm 88driver also supports the standard IBSS point-to-point mode 89where stations can communicate amongst themselves without the 90aid of an access point. 91.Pp 92The driver may also be configured to operate in hostap mode. 93In this mode a host may function as an access point (base station). 94Access points are different than operating in IBSS mode. 95They operate in BSS mode. 96They allow for easier roaming and bridge all ethernet traffic such 97that machines connected via an access point appear to be on the local 98ethernet segment. 99.Pp 100For more information on configuring this device, see 101.Xr ifconfig 8 . 102.Pp 103Devices supported by the 104.Nm 105driver come in either Cardbus or mini-PCI packages. 106Wireless cards in Cardbus slots may be inserted and ejected on the fly. 107.Pp 108The following cards are among those supported by the 109.Nm 110driver: 111.Pp 112.Bl -column -compact "D-Link DWL-AG650" "AR5212" "Cardbus" 113.Em "Card Chip Bus" 114D-Link DWL-AB650 AR5211 Cardbus 115D-Link DWL-AG520 AR5212 PCI 116D-Link DWL-AG650 AR5212 Cardbus 117Linksys WMP55AG AR5212 PCI 118Linksys WPC51AB AR5211 Cardbus 119Linksys WPC55AG AR5212 Cardbus 120Netgear WAB501 AR5211 Cardbus 121Netgear WAG511 AR5212 Cardbus 122.El 123.Sh EXAMPLES 124Join an existing BSS network (ie: connect to an access point): 125.Pp 126.Dl "ifconfig ath0 inet 192.168.0.20 netmask 0xffffff00" 127.Pp 128Join a specific BSS network with network name 129.Dq Li my_net : 130.Pp 131.Dl "ifconfig ath0 inet 192.168.0.20 netmask 0xffffff00 ssid my_net" 132.Pp 133Join a specific BSS network with WEP encryption: 134.Bd -literal -offset indent 135ifconfig ath0 inet 192.168.0.20 netmask 0xffffff00 ssid my_net \e 136 wepmode on wepkey 0x8736639624 137.Ed 138.Pp 139Join/create an 802.11b IBSS network with network name 140.Dq Li my_net : 141.Bd -literal -offset indent 142ifconfig ath0 inet 192.168.0.22 netmask 0xffffff00 ssid my_net \e 143 mode 11b mediaopt adhoc 144.Ed 145.Pp 146Create an 802.11g host-based access point: 147.Bd -literal -offset indent 148ifconfig ath0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap \e 149 mode 11g mediaopt hostap 150.Ed 151.Pp 152Create an 802.11a host-based access point with WEP enabled: 153.Bd -literal -offset indent 154ifconfig ath0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap \e 155 wepmode on wepkey 0x1234567890 mode 11a mediaopt hostap 156.Ed 157.Pp 158Create a host-based wireless bridge to fxp0: 159.Bd -literal -offset indent 160Add BRIDGE to the kernel config. 161ifconfig ath0 inet up ssid my_ap media DS/11Mbps mediaopt hostap 162sysctl net.link.ether.bridge=1 163sysctl net.link.ether.bridge_cfg="ath0 fxp0" 164sysctl net.inet.ip.forwarding=1 165.Ed 166.Pp 167This will give you the same functionality as an access point. 168.Sh DIAGNOSTICS 169.Bl -diag 170.It "ath%d: unable to attach hardware; HAL status %u" 171The Atheros Hardware Access Layer was unable to configure the hardware 172as requested. 173The status code is explained in the HAL include file 174.Pa sys/contrib/dev/ath/ah.h . 175.It "ath%d: failed to allocate descriptors: %d" 176The driver was unable to allocate contiguous memory for the transmit 177ad receive descriptors. 178This usually indicates system memory is scarce and/or fragmented. 179.It "ath%d: unable to setup a data xmit queue!" 180The request to the HAL to setup the transmit queue for normal 181data frames failed. 182This should not happen. 183.It "ath%d: unable to setup a beacon xmit queue!" 184The request to the HAL to setup the transmit queue for 802.11 beacon frames 185frames failed. 186This should not happen. 187.It "ath%d: 802.11 address: %s" 188The MAC address programmed in the EEPROM is displayed. 189.It "ath%d: hardware error; resetting" 190A nunrecoverable error in the hardware occurred. 191Errors of this sort include unrecoverable DMA errors. 192The driver will reset the hardware and continue. 193.It "ath%d: rx FIFO overrun; resetting" 194The receive FIFO in the hardware overflowed before the data could be 195transferred to the host. 196This typically occurs because the hardware ran short of receive 197descriptors and had no place to transfer received data. 198The driver will reset the hardware and continue. 199.It "ath%d: unable to reset hardware; hal status %u" 200The Atheros Hardware Access Layer was unable to reset the hardware 201as requested. 202The status code is explained in the HAL include file 203.Pa sys/contrib/dev/ath/ah.h . 204This should not happen. 205.It "ath%d: unable to start recv logic" 206The driver was unable to restart frame reception. 207This should not happen. 208.It "ath%d: device timeout" 209A frame dispatched to the hardware for transmission did not complete in time. 210The driver will reset the hardware and continue. 211This should not hapen. 212.It "ath%d: bogus xmit rate 0x%x" 213An invalid transmit rate was specified for an outgoing frame. 214The frame is discarded. 215This should not happen. 216.It "ath%d: ath_chan_set: unable to reset channel %u (%u Mhz)" 217The Atheros Hardware Access Layer was unable to reset the hardware 218when switching channels during scanning. 219This should not happen. 220.It "ath%d: unable to allocate channel table" 221The driver was unable to allocate memory for the table used to hold 222the set of available channels. 223.It "ath%d: unable to collect channel list from hal" 224A problem occurred while querying the HAL to find the set of available 225channels for the device. 226This should not happen. 227.It "ath%d: %s: %dM -> %dM (%d ok, %d err, %d retr)" 228The driver's rate control algorithm changed the current rate for transmitting 229frames. 230This message is temporarily enabled for normal use to help in diagnosing 231and improving the rate control algorithm. 232The message indicates the new and old transmit rates and the statistics 233it used to decide on this change. 234.It "ath%d: failed to enable memory mapping" 235The driver was unable to enable memory-mapped I/O to the PCI device registers. 236This should not happen. 237.It "ath%d: failed to enable bus mastering" 238The driver was unable to enable the device as a PCI bus master for doing DMA. 239This should not happen. 240.It "ath%d: cannot map register space" 241The driver was unable to map the device registers into the host address space. 242This should not happen. 243.It "ath%d: could not map interrupt" 244The driver was unable to allocate an IRQ for the device interrupt. 245This should not happen. 246.It "ath%d: could not establish interrupt" 247The driver was unable to install the device interrupt handler. 248This should not happen. 249.El 250.Sh SEE ALSO 251.Xr an 4 , 252.Xr arp 4 , 253.Xr ath_hal 4, 254.Xr card 4 , 255.Xr netintro 4 , 256.Xr pcic 4 , 257.Xr wi 4 , 258.Xr wlan 4 , 259.Xr ifconfig 8 , 260.Xr wicontrol 8 261.Re 262.Sh HISTORY 263The 264.Nm 265device driver first appeared in 266.Fx 5.2 . 267.Sh CAVEATS 268Different regulatory domains have different default channels for adhoc 269mode. 270See 271.Xr ifconfig 8 272for information on how to change the channel. 273See 274.Xr wicontrol 8 275for information on different regulatory domains. 276.Pp 277802.11g support is little tested and may have interoperabity problems. 278The software is known to function with an Atheros 11g access point but 279interoperability may be problematic until vendors update firmware in 280existing 11g products. 281If you encounter problems using an 11g access point you should be able 282to workaround incompatibilities by locking the driver to 11b mode. 283Alternatively, most 11g compatibility issues are in the 802.11 layer 284and you may be able to workaround issues by modifying the 285.Xr wlan 4 286module. 287.Pp 288Atheros Turbo mode is untested. 289.Sh BUGS 290.Pp 291Roaming mode is broken. 292If you lose your access point by going out of 293range the driver does not automaticaly re-associate. 294.Pp 295Adhoc mode is untested and possibly/probably broken. 296.Pp 297Performance in lossy environments is suboptimal. 298The algorithm used to select the rate for transmitted packets is 299very simplistic. 300There is no software retransmit; only hardware retransmit is used. 301Contributors are encouraged to replace the existing rate control algorithm 302with a better one (hint: all the information needed is availble to the driver). 303.Pp 304General performance is suboptimal. 305The Atheros hardware is known to be capable of transfer rates of 23-34 Mb/s 306(or more) in 11a and 11g modes using their NDIS (aka Windows) driver. 307Results with this driver are mixed and seem to vary significantly. 308.Pp 309It has been observed that getting a DHCP address sometimes requires 310multiple tries. 311This seems to happen only with AR5211 and AR5212 parts and mostly 312in a noisy environment (i.e. one where many access points are found). 313This problem is specific to the driver and not the hardware. 314.Pp 315The driver does not fully enable power-save operation of the chip; 316consequently power use is suboptimal. 317