Re: [PATCH 01/15] wiphy: add driver quirk for the colocated scan flag

[James Prestwood <prestwoj@gmail.com>]

Hi Denis,

On 8/26/25 7:47 AM, Denis Kenzior wrote:
> Hi James,
>
> On 8/22/25 2:51 PM, James Prestwood wrote:
>> Some drivers do not handle the colocated scan flag very well and this
>> results in BSS's not being seen in scans. This of course results in
>> very poor behavior.
>>
>> This has been seen on ath11k specifically but after some
>> conversations [1] on the linux-wireless mailing list others have
>> reported issues with iwlwifi acting similarly. Since there are many
>> hardware variants that use both ath11k and iwlwifi this new quirk
>> isn't being forced to those drivers, but let users configure IWD to
>> disable the flag if needed.
>>
>> [1] 
>> https://lore.kernel.org/linux-wireless/d1e75a08-047d-7947-d51a-2e486efead77@candelatech.com/
>
> So why does dropping the colocated flag help?  You have a 2/5 G 
> network that isn't related to the 6G network at all, meaning that 
> there is no RNR element. Hence 6G must be scanned passively on social 
> channels.  If you don't add the colocated flag, the end result should 
> be the same, no?  Or is colocated flag forcing the use of RNR element 
> only?

We noticed this issue specifically with a 6Ghz-only network. So in 
theory there should have been no RNR element at all... Despite this, and 
performing full spectrum scans, we would get a very limited set of BSS's 
back on 6ghz. I suspect maybe the kernel was only scanning social 
channels, but removing the colocated flag got things working as I would 
expect.

I asked the question, and Ben said he saw similar behavior on iwlwifi. 
Its likely an oversight in the kernel. It would be nice to fix there, 
but my dedication to fixing the kernel is ever dwindling. Based on my 
testing after removing the flag I opted for a one-line workaround...

>
>> ---
>>   src/wiphy | 23 +++++++++++++++++------
>>   src/wiphy.h |  1 +
>>   2 files changed, 18 insertions(+), 6 deletions(-)
>>
>
> Anyway, I went ahead and applied patches 1-4.
>
> Regards,
> -Denis