Re: wcn7850 issues

[Kalle Valo <kvalo@kernel.org>]

Janusz Dziedzic <janusz.dziedzic@gmail.com> writes:

> wt., 3 wrz 2024 o 09:47 Kalle Valo <kvalo@kernel.org> napisał(a):
>>
>> + linux-wireless
>>
>> david Atkins <david@3adesign.co.uk> writes:
>>
>> > ...
>> >> >>>         Ext Tag: EHT Operation (802.11be D3.0)
>> >> >>>             Ext Tag length: 8 (Tag len: 9)
>> >> >>>             Ext Tag Number: EHT Operation (802.11be D3.0) (106)
>> >> >>>             EHT Operation Parameters: 0x01, EHT Operation Information
>> >> Present
>> >> >>>                 .... ...1 = EHT Operation Information Present: True
>> >> >>>                 .... ..0. = Disabled Subchannel Bitmap Present: False
>> >> >>>                 .... .0.. = EHT Default PE Duration: False
>> >> >>>                 .... 0... = Group Addressed BU Indication Limit: False
>> >> >>>                 ..00 .... = Group Addressed BU Indication Exponent: 0
>> >> >>>                 00.. .... = Reserved: 0x0
>> >> >>>             Basic EHT-MCS And Nss Set: 0x44444444
>> >> >>>             Control: 0x02, Channel Width: 80 MHz EHT BSS bandwidth
>> >> >>>                 .... .010 = Channel Width: 80 MHz EHT BSS bandwidth (2)
>> >> >>>                 0000 0... = Reserved: 0x00
>> >> >>>
>> >> >>> Are you saying the ath12k driver does not support these features? If
>> >> >>> not can
>> >> >> you clarify the issue so I can raise with the AP team.
>> >> >>>
>> >> >> ath12k/WCN7850 supports EHT, but with NSS only 2. Here the AP
>> >> >> requires NSS to be no less than 4, that is why EHT connection was disabled.
>> >> >
>> >> > Which field is requiring NSS of 4, I'm only seeing a maximum of 4, the
>> >> Qualcomm windows driver will connect to the same AP, we had assumed that
>> >> that ath12k would do the same.
>> >> Basic EHT-MCS And Nss Set: 0x44444444
>> >
>> > My understanding of the spec is that there are maximum numbers of
>> > streams though, are you saying the AP has to advertise 0x22222222
>> > which would then prevent a 4x4 client (say an extender) from
>> > connecting with 4 streams? I note that the Qualcomm windows driver for
>> > Hamilton works with the AP and an Intel BE200 also works both of which
>> > will be in at most 2x2
>>
>> Did you test Intel BE200 with the Windows driver? Johannes mentioned
>> that ieee80211_verify_sta_eht_mcs_support() in mac80211 checks this so I
>> would assume that iwlwifi also behaves like ath12k.
>
> Yes, this is AP issue - hostapd fix required - advertise 0x11111 ...
> In other case station  < 4nss will drop to HE only.

Thanks. And Johannes pointed out that you had even discussed about this
before:

https://lore.kernel.org/linux-wireless/CAFED-jk8pJheJEViESnE54f-K+JgRMiWoiCSa0GBt=RKaCn7sw@mail.gmail.com/

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