[PATCH V13 8/9] wifi: ath12k: add support for 160 MHz bandwidth

[Pradeep Kumar Chitrapu]

On 5/22/2025 1:34 AM, Nicolas Escande wrote:
> On Wed May 21, 2025 at 11:38 PM CEST, Pradeep Kumar Chitrapu wrote:
> [...]
>> Thanks Nicolas,
>>
>> I believe IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ mean only
>> 80PLUS80 not both 160 and 80PLUS80 and STA must set
>> IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ flags for indicating 160 MHz
>> support. Please correct me if my understanding is correct. However I
>> agree that we must allow STA to connect irrespective of which flag STA
>> sets as long as bandwidth is 160MHz. I see ath10k and ath11k also allows
>> this by setting default phymode of MODE_11AC_VHT160 for BW
>> ==IEEE80211_STA_RX_BW_160 case.
>> I will make this change in next revision.
>> Thanks
>> Pradeep
> 
> Hello Pradeep,
> 
> Well this is quite unclear for me maybe Johannes or someone more aware of the
> evolutions of the standard could shime in.
> 
>  From what I've gathered:
>    - the naming IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ implies both
>      which points it was the case when added
>    - and the original 802.11ac-2013 Table 8-183v states:
> 	Set to 0 if the STA does not support either 160 or 80+80 MHz.
> 	Set to 1 if the STA supports 160 MHz.
> 	Set to 2 if the STA supports 160 MHz and 80+80 MHz.
> 	The value 3 is reserved.
> 
> Things get complicated after:
>   - later versions like 802.11-2020 have deprecated value 2 in favor of the new
>     Extendeed NSS BW feature
>   - Table 9-272 still implies both 160 & 80+80
>   - Table 11-23 & Table 11-24 implies only 80+80 but both talk about the
>     'VHT Operation' Channel Width field and not the 'VHT Capabilities' Supported
>     Channel Width. And thoses had different values even in the first AC amendment
> 
> So it feels like when no Extended NSS BW Support is used (first gen AC devices),
> IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ really means both 160 & 80+80
Thanks Nicolas for detailed response.
Request you to kindly review V14 series and let me know if it works?

Thanks
Pradeep