BLE Split Link Layer Improvements

[carlescufi]

This issue lists all the improvements we want to include that are not part of bringing the Split Link Layer up to parity with the existing one (#12681).

• Add support for Controller (SW deferred)-based Privacy (BLE controller: Add support for Controller(SW deferred)-based Privacy #14621)
• Change the role dependent event-done handling from type switch-case to callback concept.
• Move the LLL event prepare/resume queue/handling into LLL. (@cvinayak )
• Move the LLL-to-ULL Tx ack queue API to ULL domain.
• Add documentation for ticker @stko-ot
• Include the diagrams done by @pskhansen in the documentation
• Robustness fix (nice to have): bluetooth: controller: Check on done queue performed too late #13389
• Add tests in nrf52_bsim to run on upstream CI for (at least basic) controller functionality
• Style fixes (Failing LL.TS Data Length Update Tests (split) #22048)
• Create a porting guide to help users port to new radio hardware

[aescolar]

"- [ ] Use atomic_cas when supported by the arch without disabling interrupts (see for more info)"
was removed due to #13471 being closed

[aescolar]

"- [ ] Add support for (current) Mesh Extensions (#14678)"
removed as there was no real interest for that, and the ticket was morphed into adding full mesh extensions to the controller.

[cfriedt]

Ooooo - I like this! It might also be a good idea to add a basic / minimum recommendation and documentation for the radio API. Naturally, most chips will have a different radio, but we are mostly using the same interface so far. However, that interface is largely undocumented. Some state diagrams would be nice as well.

[carlescufi]

Ooooo - I like this! It might also be a good idea to add a basic / minimum recommendation and documentation for the radio API. Naturally, most chips will have a different radio, but we are mostly using the same interface so far. However, that interface is largely undocumented. Some state diagrams would be nice as well.

Just added a point at the end, thanks!

[joerchan]

Add tests in nrf52_bsim to run on upstream CI for (at least basic) controller functionality

Isn't this done?

[kruithofa]

@carlescufi we close this issue since realistically no work will be done on this

[KlemenDEV]

realistically no work will be done on this

Will the split LL ever be "official", or should we use the old system?

[cvinayak]

realistically no work will be done on this

Will the split LL ever be "official", or should we use the old system?

Split Link Layer is the default upstream since Zephyr v2.0.0-rc1 , see 6cf26b8

[KlemenDEV]

I see, thanks!