Go back –> [[en/users/Drivers/Atheros|Atheros Linux wireless drivers]] 


===== ath9k_htc =====

ath9k_htc provides hardware support for Atheros AR9001 and AR9002 family hardware. 

 


===== Get the driver =====

The driver is part of wireless-testing. See this [[en/developers/Documentation/git-guide|guide]] to use the wireless-testing tree directly. Or you can use [[en/users/Download|compat-wireless]] to get the driver. 


===== Chipsets supported =====
  * AR9271 
  * AR7010 USB-PCIe bridge with AR928x wireless chips 
===== Supported Devices =====

See the [[en/users/Drivers/ath9k_htc/devices|ath9k_htc device list]]. 


===== Mailing list =====

[[en/developers/mailinglists|linux-wireless]] is the recommended mailing list to use for questions regarding the driver. Firmware-related questions should go to [[http://lists.infradead.org/mailman/listinfo/ath9k_htc_fw|ath9k_htc_fw]].

The archives for the old ath9k-devel list, which was closed in 2017, are available [[https://lists.ath9k.org/mailman/listinfo/ath9k-devel|here]].

===== Configuring your kernel =====

Enable these options in your kernel config. Most distros will already have it enabled. 


<code>CONFIG_ATH_COMMON=m
CONFIG_ATH9K_HW=m
CONFIG_ATH9K_COMMON=m
CONFIG_ATH9K_HTC=m</code>

===== Firmware =====

This driver requires firmware. The firmware can be obtained from [[http://git.kernel.org/?p=linux/kernel/git/firmware/linux-firmware.git|firmware tree]]. 

Alternately you can download it from here: [[http://wireless.kernel.org/download/htc_fw/|http://wireless.kernel.org/download/htc_fw/]]. 

[[en/developers/GSoC/2012/ath9k_htc_open_firmware|This firmware is now open]], to contribute check out: 
      * [[https://github.com/qca/open-ath9k-htc-firmware|https://github.com/qca/open-ath9k-htc-firmware]] 


<code>Older firmware map:

AR9271 - ar9271.fw
AR7010 - ar7010.fw or ar7010_1_1.fw</code>
<code>Newer firmware map:

AR9271 - htc_9271.fw
AR7010 - htc_7010.fw</code>
The firmware has to be placed in the correct location, usually /lib/firmware. This could vary among distributions, so check your distro's policies if loading of the firmware fails. 


===== Supported Features =====
        * Station Mode 
        * Monitor Mode 
        * AP Mode (**NOTE:** AP mode works only with up to 7 stations due to a [[https://lists.ath9k.org/pipermail/ath9k-devel/2013-April/010513.html|firmware limitation]]) 
        * IBSS Mode 
        * Mesh Mode 
        * Legacy (11g) operation 
        * HT support 
        * TX/RX 11n AMPDU aggregation 
        * HW Encryption 
        * LED 
        * Suspend/Resume 
===== Disabled Features =====
          * [[PowerSave|PowerSave]] 

ath9k_htc uses the Autosleep feature of the wireless card. Basic PS support has been implemented in the driver, but it is disabled by default. 


===== Modeswitching for AR7010 =====

AR7010 based cards operate by default in USB Mass storage mode and have to be 'switched' to wireless mode on plugging in. If you have an old [[http://www.draisberghof.de/usb_modeswitch/|USB_ModeSwitch]] package, you can do this to load ath9k_htc automatically. 

Add this line to /lib/udev/rules.d/40-usb_modeswitch.rules. 


<code># Atheros Wireless
ATTRS{idVendor}=="0cf3", ATTRS{idProduct}=="20ff", RUN+="usb_modeswitch '%b/%k'"</code>
Add a file **"0cf3:20ff"** in /etc/usb_modeswitch.d/ and add these lines to it. 


<code>########################################################
# Atheros Wireless

DefaultVendor= 0x0CF3
DefaultProduct=0x20FF

TargetVendor=  0x0CF3
TargetProduct= 0x7010

CheckSuccess=10
NoDriverLoading=1

MessageContent="5553424329000000000000000000061b000000020000000000000000000000"</code>
Now, when the device is plugged in, ath9k_htc should load normally. If not, report to [[https://lists.ath9k.org/mailman/listinfo/ath9k-devel|ath9k_devel]]. 


===== Debugging =====

See [[en/users/Drivers/ath9k/debug|here]]. 


===== Known issues =====

  * The AMPDU size is limited to 22 subframes for UB94/95 and 17 for UB91. Fixing this would require removing lots of cruft and structural changes in the firmware.
  * This HW strongly depends on USB.  Please chech [[https://github.com/qca/open-ath9k-htc-firmware/wiki/usb-related-issues|usb related issues]] before sending bug report.
===== AP/P2P Modes =====

//**This is experimental !**// 

Patches enabling P2P/AP modes have been merged in wireless-testing, it would be part of the driver from Linux 3.0. Using only one VIF (Virtual Interface) running in AP mode would be a good idea for now, multiple interface support has not been tested extensively. Note: [[PowerSave|PowerSave]] is not properly supported yet. 

Please do report bugs, crashes, weird behavior and other general tantrums thrown by the driver. 


===== TODO =====

A list of things that need to be fixed in the firmware. 
            * Handle AMPDU subframe limits properly. 
            * Handle AMPDU density properly. 
            * ERP protection needs to be fixed. 
            * RTS/CTS has to be handled properly (for both management and data frames). 
            * Processing multicast frames has to be fixed ([[MultiRateRetry|MultiRateRetry]] etc.). 
            * Short/Long preamble selection has to be fixed. 
            * Duration calculation for data, control and management frames. 
            * BAR transmission to be moved to the host. 
            * Low RSSI issue for UB91/94. 
            * TPC for UB94/95 - why is it required ? 
            * NOACK handling. 
            * Destination mask handling. 
            * TX filtering (legacy and HT modes). 
            * AMPDU delimiter calculation. 
            * [[AccessClass|AccessClass]] distribution. 
            * Unify TX statistics. 
            * MIB interrupt processing (how the fsck does ANI even work now ?) 
            * cwMin/cwMax handling. 
            * _Three_ different data structures pointing to the same rate control data, really ? 
            * Multicast frame completion. 
            * World poverty. 
            * [[en/developers/GSoC/2012/ath9k_htc_open_firmware|open firmware for ath9k_htc]]