Re: Force use of 5GHz band

[James Prestwood <prestwoj@gmail.com>]

Hi Denis,

On 9/15/23 7:47 AM, Denis Kenzior wrote:
> Hi James,
> 
>>> Careful about using high factors like this.  Right now the rank is 
>>> computed using a double, but truncated to a uint32_t and clamped to 
>>> USHRT_MAX / uint16_t.  This works fine, but the FT roaming 
>>> calculation is a bit more careless.  Could lead to very funny results.
>>
>> I don't think FT uses that ranking factor, but either way yes some 
>> huge factor like that shouldn't be needed.
>>
> 
> Right, but it uses another factor and truncates to a uint16_t.  So if 
> you have USHRT_MAX as rank, multiply then truncate -> fun things happen.
> 
>>>
>>> We may be better off introducing 2.4GHz factor and suggesting using a 
>>> 0.0 multiplier to turn bands off.  Or add an explicit setting.
>>
>> I actually was thinking this would be nice. We actually don't even run 
>> a 2.4ghz network at all so that would reduce extra scanning cycles, 
>> even if just a couple seconds. I'll go ahead and add support for 0.0 
>> factors disabling the band, and add a 2.4 factor setting.
> 
> Excellent.

How would you prefer I do this? We've got quite a few modules using scan 
APIs so I question if we want to filter the frequencies before calling 
scan_*

If we filter in scan.c and call back as if the scan returned no results 
we shouldn't need to touch anything except scan.c. The downside is its a 
bit of wasted work doing this since we have to create requests and work 
items for nothing, but the alternative of adding this specific logic to 
each module using scan calls seems worse IMO, what do you think?

> 
> Regards,
> -Denis