[PATCH 61/76] wifi: nl80211: add EML/MLD capabilities to per-iftype capabilities

[Wen Gong]

On 8/11/2023 5:08 PM, Johannes Berg wrote:
> On Fri, 2023-08-11 at 17:05 +0800, Wen Gong wrote:
>> On 8/11/2023 5:03 PM, Johannes Berg wrote:
>>> On Fri, 2023-08-11 at 11:51 +0800, Wen Gong wrote:
>>>> Now there are many nl80211_band such as NL80211_BAND_2GHZ/
>>>> NL80211_BAND_5GHZ/NL80211_BAND_6GHZ... In the same interface, if some bands
>>>> support EML, and other bands not support EML, then how to handler this
>>>> case?
>>> But ... these are MLD capabilities, not of the (associated) STA?
>> Yes, I know it.
> Then you can't honestly be suggesting we move "MLD capa and ops" into
> per-band, no?
I know it just now after I send the suggestion😁
>>> So not sure how that would make sense? What would you even _do_ with
>>> that?
>> I think another change is not move "u16 eml_capabilities", and only add
>> a new
>> field "u16 eml_supp_bands" together with the "u16 eml_capabilities", the
>> eml_supp_bands is filled with the bit map of enum nl80211_band. Is that OK?
>>
> And again, what would you do with it? Not advertise EML when you have
> selected links that are not in the map? And if the links change
> dynamically in the future? You'd probably need a bunch of validation for
> that.
For example, for station, NOT support EML on 2 GHz, support EML on 5 
GHz/6 GHz.

When connect to 2/3 links AP, then EML should NOT add in assoc req while 
connect
to AP which is 2 GHz+5 GHz or 2 GHz+6 GHz or 2 GHz+5 GHz+6 GHz.

EML should add in assoc req while connect to AP which is 5 GHz+6 GHz.

For dynamic link change, it is another new topic, so I have not good advise
for that.😁
>
> And usually you'd probably always connect to all the bands?
>
> I really don't get it.

Sometimes AP is 3 links (2 GHz+5 GHz+6 GHz), but station only support 2 
links,

then station will not connect all bands, station need choose 2 bands to 
connect.

>
> Btw this is all client - so your client implementation can just not send
> the EML action frame (forgot the name right now) when the currently
> active links are not compatible.
I guess you are refer to "EML Operating Mode Notification frame".
> johannes