[ath9k-devel] Radar Detection and DFS status

[Alexander Egorenkov <egorenar@gmail.com>]

Am 29.04.2010 22:15, schrieb Benoit PAPILLAULT:
> Robert Meschke a ?crit :
>> Hi,
>>
>> thank you for your immediate response, Luis. It's a pity that DFS is not supposed to work in the near future. A can provide more specific information. I am working on a project, where I really need the 5 Ghz band and have to respect national laws.
>> I am using Ubiquiti Networks SR71-A MIMO mini pci radios, based on the Atheros AR 9160 bb/mac chip and AR5133 RF chip. I am really willing to implement DFS if it is somehow possible for me.
>> Former in this thread it was mentioned that Radar Pulse Detection is done by hardware itself and is supported by madwifi. I've checked the madwifi-hal and the one of Sam Leffler for Radar Detection stuff. The AR9160 is declared as compatible with AR5416 in the ah_devid.h:
>>
>> /* AR5416 compatible devid's  */
>> #define AR5416_DEVID_PCI    0x0023          /* AR5416 PCI (MB/CB) Owl */
>> #define AR5416_DEVID_PCIE    0x0024          /* AR5416 PCI-E (XB) Owl */
>> #define AR9160_DEVID_PCI    0x0027          /* AR9160 PCI Sowl */
>> #define AR9280_DEVID_PCI    0x0029          /* AR9280 PCI Merlin */
>> #define AR9280_DEVID_PCIE    0x002a          /* AR9280 PCI-E Merlin */
>> #define AR9285_DEVID_PCIE    0x002b          /* AR9285 PCI-E Kite */
>>
>> Register adresses for Radar Detection are defined for AR5211+ in if_ath_radar.h. In the if_ath_radar.c this can be found:
>>
>> if (ar_device(sc)>= 5211) {
>>
>> ...
>>
>> }
>>
>> It implies to me that Radar Detection performed by the madwifi Driver could possibly work for AR5416 (and therefore for AR9160, too).
>>
>> It has to be mentioned that there are register adress definitions for Radar Detection in the hal of Sam Leffler but only for AR5211 and AR5212 and I've read in forum that the AR5416 does not have Radar Detection caps.
>>
>> Are the hardware interfaces for Radar Detection of AR9160 and AR5211/12 the same and is there any chance for madwifi code to work for ath9k too (after necessary modifications)?
>>
>> Have anybody else information on this topic? I have access to signal generators an spectrum analysers, so I could verify compliance with DFS but I need the exact hardware specifications.
>> Thanks in advance.
>>
> Hi Robert,
>
> If you have access to signal generators, I would suggest a very simple
> and easy start : try to add the code to detect pulse like it was done in
> madwifi-dfs (ported to madwifi/trunk BTW). Then, just send few pulses
> and you'll see if you AR9160 based card will detect it. This is how I
> did when writing madwifi-dfs... a long time ago :-).
>
> Maybe 802.11n hardware has some stuff specific to radar detection since
> it probably needs to distinguish between primary&  secondary channel. Is
> there someone (Luis?) that can confirm?
>
> Regards,
> Benoit

And AR9160 definetly supports DFS :-) Because it's a chipset for AP and 
routers for 2.4 and 5 GHZ band :-)
See http://www.atheros.com/news/AR9001.htm