wcn7850 issues

[Janusz Dziedzic]

wt., 3 wrz 2024 o 23:15 david Atkins <david at 3adesign.co.uk> napisał(a):
>
> > > wt., 3 wrz 2024 o 09:47 Kalle Valo <kvalo at kernel.org> napisał(a):
> > >>
> > >> + linux-wireless
> > >>
> > >> david Atkins <david at 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 at mail.gmail.com/
> >
>
> So this
>
> Basic EHT-MCS And Nss Set: 0x44444444
>
> Should be 0x11111111 ? and it defines the minimum number of streams needed to connect?
>
> This the defines the max streams ?
>
>             Supported EHT-MCS and NSS Set
>                 EHT-MCS Map (BW <= 80MHz): 0x444444
>                     .... .... .... .... .... 0100 = Rx Max Nss That Supports EHT-MCS 0-9: 4
>                     .... .... .... .... 0100 .... = Tx Max Nss That Supports EHT-MCS 0-9: 4
>                     .... .... .... 0100 .... .... = Rx Max Nss That Supports EHT-MCS 10-11: 4
>                     .... .... 0100 .... .... .... = Tx Max Nss That Supports EHT-MCS 10-11: 4
>                     .... 0100 .... .... .... .... = Rx Max Nss That Supports EHT-MCS 12-13: 4
>                     0100 .... .... .... .... .... = Tx Max Nss That Supports EHT-MCS 12-13: 4
>
You mix different things:

Supported EHT-MCS and NSS set  vs Basic EHT-MCS And Nss Set