Subject: Re: linux-next: Signed-off-by missing for commit in the drm-misc tree

From: Daniel Vetter <[email-masked]>
Date: Thu, 16 Nov 2023 09:27:58 +0100

On Thu, Nov 16, 2023 at 09:11:43AM +0100, Maxime Ripard wrote:
> On Tue, Nov 14, 2023 at 06:46:21PM -0500, Luben Tuikov wrote:
> > On 2023-11-13 22:08, Stephen Rothwell wrote:
> > > BTW, cherry picking commits does not avoid conflicts - in fact it can
> > > cause conflicts if there are further changes to the files affected by
> > > the cherry picked commit in either the tree/branch the commit was
> > > cheery picked from or the destination tree/branch (I have to deal with
> > > these all the time when merging the drm trees in linux-next).  Much
> > > better is to cross merge the branches so that the patch only appears
> > > once or have a shared branches that are merged by any other branch that
> > > needs the changes.
> > > 
> > > I understand that things are not done like this in the drm trees :-(
> > 
> > Hi Stephen,
> > 
> > Thank you for the clarification--understood. I'll be more careful in the future.
> > Thanks again! :-)
> 
> In this case, the best thing to do would indeed have been to ask the
> drm-misc maintainers to merge drm-misc-fixes into drm-misc-next.
> 
> We're doing that all the time, but we're not ubiquitous so you need to
> ask us :)
> 
> Also, dim should have caught that when you pushed the branch. Did you
> use it?

Yeah dim must be used, exactly to avoid these issues. Both for applying
patches (so not git am directly, or cherry-picking from your own
development branch), and for pushing. The latter is even checked for by
the server (dim sets a special push flag which is very long and contains a
very clear warning if you bypass it).

If dim was used, this would be a bug in the dim script that we need to
fix.

Also backmerges (and in generally anything that is about cross-tree patch
wrangling, like cherry-picking) are maintainer duties in drm-misc and not
for committers:

https://drm.pages.freedesktop.org/maintainer-tools/maintainer-drm-misc.html#maintainer-s-duties

I think it'd be really good for Luben to go through the docs and supply a
patch to clarify this, if it's not clear from the existing docs.

We have some wording in the committer docs, but maybe it's not clear
enough:

https://drm.pages.freedesktop.org/maintainer-tools/committer-drm-misc.html#merge-criteria

"Any non-linear actions (backmerges, merging topic branches and sending
out pull requests) are only done by the official drm-misc maintainers (see
MAINTAINERS, or ask #dri-devel), and not by committers. See the examples
section in dim for more info"

Minor screw-ups like this gives us a great opportunity to improve the
tooling&docs, let's use it.

Cheers, Sima
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch