Question of Verification about AK FW patch tip

Hi, Communities ;

As I knew that AK FW has two versions.

One is minor version and second is micro version.

e.g. 2013.06.05.<minor-version>.<micro-version>,<external-build-number>

My Cu has 2011Q1.4.0 (2011.04.24.4.0.1.1.21) on 7120.
We have to plan to upgrade it (target fw version is 2013Q1.2.9).

How to upgrade fw procedure version ?

which step is correct ?

Case 1 > 2011Q1.4.0 -> 2011Q1.4.2 -> 2013Q1.0.1 -> 2013Q1.2.0 -> 2013Q1.2.9
Case 2 > 2011Q1.4.0 -> 2011Q1.4.2 -> 2013Q1.0.1 -> 2013Q1.2.9
Case 3 > 2011Q1.4.0 -> 2011Q1.4.2 -> 2013Q1.2.9

I would like to verify the AK FW upgrade role.
Some FW has mentioned the specific procedure on each release note.

If there be a role to adopt fw step version, it is very helpful to upgrade.