Re: [PATCH] mac80211: check if channels allow 80 MHz for VHT probe requests

[Arend van Spriel <arend@broadcom.com>]

On 11/25/14 15:18, Johannes Berg wrote:
> On Tue, 2014-11-25 at 22:13 +0800, YanBo wrote:
>
>>> But is all of that really the right way? I'm not completely convinced.
>>
>> Except set the flag, the HW itself should support this feature, or
>> else it also doesn't work, I'd
>> send the patch in soon for public review.
>
> Yeah, but is it really the right way to advertise VHT? In the spec, VHT
> means you also have 80 MHz support - do you really think you can/will do
> 80 MHz on 2.4 GHz? Seems like all of this will cause more corner cases.

For brcmfmac, the 80 MHz requirement in the spec was exactly the reason 
to *not* advertise VHT in 2.4G.

>>>
>>> I guess we can make this check conditional for 5GHz when the VHT support
>>> lands and is discussed.
>>>
>> That is sounds good if it only check for 5GHz for what I know CMIIW.
>
> Even on 2.4 GHz it technically isn't enough though - there's enough
> spectrum in 2.4 GHz for a single 80 MHz channel; how long until somebody
> wants to do *that* for some reason? But the rest of us really doesn't
> think that's applicable ...

To get "friendly" with your neighbors :-p

Regards,
Arend

> Anyway, it probably needs mac80211 patches anyway since mlme.c already
> disables VHT if you can't do 80 MHz, so I think you should post those as
> part of a bigger discussion about how we want to support it and what it
> really means etc.
>
> johannes
>
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