Re: VHT 160Mhz and nss related config.

[Adrian Chadd <adrian@freebsd.org>]

.. or give us a legit way to acquire the 2016 spec? :)

Curious implementers want to know!



-a

On 13 February 2017 at 11:21, Ben Greear <greearb@candelatech.com> wrote:
> On 02/12/2017 11:06 PM, Johannes Berg wrote:
>>
>> On Fri, 2017-02-10 at 14:58 -0800, Ben Greear wrote:
>>>
>>> So, it appears that the ath10k QCA9984 4x4 160Mhz chip can do 4x4
>>> MIMO at VHT80, but
>>> it can do only 2x2 MIMO at VHT160/80+80.
>>>
>>> When configuring a peer, we need to tell the firmware the number of
>>> spatial streams
>>> of the peer at VHT160 and at VHT80 and lower.  They are not the same
>>> value.
>>>
>>> I cannot think of any standard way to get this information based on
>>> VHT capabilities and such.  Currently, one could just assume VHT160
>>> NSS is 1/2 of the VHT80 NSS, but that is unlikely to be true for all
>>> vendors.
>>
>>
>> This was recently added to the VHT capabilities in the spec, see Table
>> 9-250 in 802.11-2016.
>>
>> johannes
>>
>
> I don't have that spec...maybe you could post a patch that adds that flag
> and/or other fields to the appropriate header files?  I can attempt to
> add support to ath10k after that...
>
>
> Thanks,
> Ben
>
> --
> Ben Greear <greearb@candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com
>