don't base trees on 5.12-rc1

[Dave Airlie]

On Wed, 10 Mar 2021 at 17:48, Maxime Ripard <maxime at cerno.tech> wrote:
>
> Hi Dave,
>
> On Wed, Mar 10, 2021 at 09:50:29AM +1000, Dave Airlie wrote:
> > I'm mostly sending this to the -misc maintainers because
> > drm-misc-fixes is based on rc1 at present.
> >
> > This needs to be *rebased* not merged up to 5.12-rc2. Merging will
> > still have the bad landmine commits in the bisect history. This is a
> > very special case.
>
> I'm sorry, I'm not entirely sure I get this. -rc1 is still in the -rc2
> history, so how would that change anything in the bisect history?
>

We can't get rid of the bad commit range, we can reduce the amount of
times someone accidentally bisects into it, by not using it as a base
commit for future changes.

If in the future a bisect happens to want to test one of the patches
in drm-misc-fixes that is based on rc1, it will land the user with an
rc1 test kernel and could eat their swapfile/disk. We can avoid that
problem by not using rc1 as a base for drm-misc-fixes.

We can't avoid them bisecting into the broken commits between when
this landed and was fixed, but rebasing trees can minimise the chances
of this when bisecting other changesets.

Dave.