[PATCH] [SRU] [b/master][b/snapdragon] separate linux-snapdragon into its own topic kernel

[Kleber Souza]

On 3/20/19 9:31 AM, Paolo Pisati wrote:
> BugLink: https://bugs.launchpad.net/bugs/1820868
> 
> Impact:
> 
> During the Bionic cycle, a decision was made to incorporate the linux-snapdragon
> kernel into the master branch, thus reducing the number of topic kernels and the
> stable maintenance burden.
> 
> But as time passed and new patches were produced by Qualcomm, incorporating them
> into master while avoiding to destabilize generic became more and more
> problematic, down to the point where it was not a viable approach
> anymore.
> 
> At that point, the decision was made to fork out linux-snapdragon into its own
> topic kernel (e.g. linux-raspi2), giving more room to incorporate new code
> coming from the Qualcomm tree and avoiding to destabilize any other target in
> generic.
> 
> Fix:
> 
> This is a three step process:
> 
> 1) disable building linux-snapdragon from master by applying the attached patch
> to bionic/master
> 
> 2) create a new bionic/linux-snapdragon branch and reset hard to my
> lp:snapdragon-topic-kernel branch  (see the pull request below)

Just to make sure I'm not missing something, does this mean the following
reference from the PR?

https://git.launchpad.net/~p-pisati/ubuntu/+source/linux 8f0d0ff453a88818b597fd3828157c7b9312e36f

> 
> 3) update bionic-meta to point to the new bionic/linux-snapdragon kernel

Do we have a patch for this change? I haven't found it in this thread.

> 
> Regression potential:
> 
> From the point of view of bionic/master, this pull request doesn't introduce any
> substantial change, and in the future will let us purge generic from several
> external patches.
> 
> While from the point of view of linux-snapdragon, with ~600 code commits and ~4k
> config changes, this represent a brand new kernel and while great care was used

Could these ~4k config change commits be squashed into a single commit named like
"initial snapdragon config"?

Having this amount of commits will make rebase take much longer than probably needed.


> while putting together this branch, there's clearly a regression potential here
> but we can't leave linux-snapdragon stagnate behind the curve, so the sooner we
> bite the bullet, the better we can the deal with the eventual fallout.
> 
> --
> 
> The following changes since commit 53f4f4b0576f627345fb3769fdd6d20b6249dd91:
> 
>   UBUNTU: Ubuntu-4.15.0-47.50 (2019-03-13 04:37:50 +0000)
> 
> are available in the git repository at:
> 
>   https://git.launchpad.net/~p-pisati/ubuntu/+source/linux 8f0d0ff453a88818b597fd3828157c7b9312e36f
> 
> for you to fetch changes up to 8f0d0ff453a88818b597fd3828157c7b9312e36f:
> 
>   UBUNTU: Ubuntu-snapdragon-4.15.0-1050.53 (2019-03-19 10:43:36 +0100)
>