Discussion on commit "MLD: Scan the channels of missing links for the ML probe"

[Michael-cy Lee (李峻宇)]

Hi Louis Kotze,
 
Thank you for sending the revert and for your detailed analysis.

> 
> What I have in mind for the follow-up:
> 
> - The ML probe request itself stays exactly as it is today: the
> association link's channel, Address 3 set to that AP's BSSID, and the
> Multi-Link element listing the missing links.
> 
> - Only if links are still missing after that, one further scan
> request
> per remaining link, on that link's channel and with Address 3 set to
> the affiliated AP's own BSSID. Both are already known from the RNR
> information in the association link's scan entry. No Multi-Link
> element is needed on those, since the AP's own Probe Response frame
> carries what is missing.

We agree with your follow-up idea.

> There is also a testability gap that I should have noticed earlier.
> The
> case this was addressing is an AP MLD that does not return complete
> per-STA profiles for the requested links, and hostapd always returns
> them, so it cannot be reproduced in the hwsim tests. Would a
> CONFIG_TESTING_OPTIONS parameter on the AP side to omit requested
> per-STA profiles from the ML probe response be acceptable? That would
> give the follow-up test coverage rather than leaving it resting on a
> single AP observation.

We don't have any strong opinions on adding tests for this.

> 
> If MediaTek would be able to test the follow-up on an AP MLD, that
> would
> be very welcome.

Sure, we can help test your follow-up idea once it's ready.


Best, 
Michael