Upgrading sdk 2.6.1 to 3.1.1 broke MCUmgr

[robert.grady]

I upgraded my sdk from 2.6.1 to 3.1.1 and after resolving a few issues everything was working just as it was before the upgrade except for MCUmgr. When I run the MCUmgr client on my PC after the upgrade, the server on the nRF52850 does not reply to any requests. It's difficult to know exactly what is happening.  I don't get any error messages. No replies.  Eventually the client just times out. This works perfectly under sdk 2.6.1.

Is that anything additional I have to do?  A special Kconfig? Is there a release note that discusses this issue?  

[nordicator_prim3]

I remember running into this as well when upgrading from 2.6.0 to 2.8.0. I had originally based my mcumgr functionality on the smp_svr example. After trying to upgrade I had to get the smp_svr sample from 2.8.0 which had some different Kconfigs and subtly different app structure. I would try looking at the sample app with the version you wanted to use.

Any changes that happened between releases should be in the release notes and migration guides if you haven't checked there yet. If they aren't there in the nordic docs you may have to check the release notes from the actual zephyr repo as well. That's a pain sometimes, so I'd recommend looking at the smp_svr example first.

Hope this helps.