[PATCH v9 6/9] wifi: ath12k: add support for setting fixed HE rate/GI/LTF

[Pradeep Kumar Chitrapu]

On 1/28/2025 11:13 AM, Maxime Bizon wrote:
> 
> On Tue, 2025-01-28 at 10:44 -0800, Pradeep Kumar Chitrapu wrote:
> 
> 
> Hello,
> 
> 
>> Currently default is configured as FORCE_SGI
> 
> "Currently" with or without your patch applied ?
> 
>  From my perspective:
>   - without your patch: DEFAULT_SGI
>   - with your patch applied, no fixed rate: FORCE_SGI
>   - with your patch applied, fixed rates: user decides
> 
Hi Maxime

Yes, your understanding is correct..

This is detailed explanation.

In 11n, 11ac, the supported Guard intervals are
0.4usGI (Short GI)  - enum value used for this in firmware  - 1
0.8usGI (Long GI)   - enum value used for this in firmware  - 0

If peer support SGI, param_value 1 is sent to firmware where firmware 
switches between SGI/LGI based on packet error rate. This param value 1
corresponds to NL80211_TXRATE_FORCE_SGI in nl80211.

If user overrides this by setting default GI specifically, then we will 
override this config to send enum 0 to use LGI always irrespective of 
PER in firmware. Using SGI would slightly give a better throughput.

FW uses 0.8us GI by default for 11ax and 11be.

Hope this helps!

Thanks
Pradeep