dim question: How to revert patches?

[Daniel Vetter]

On Thu, Apr 14, 2022 at 10:37:55PM +0200, Helge Deller wrote:
> Hello dri-devel & dim users,

Apologies for late reply, I'm way behind on stuff.

> I committed this patch to the drm-misc-next branch:
> 
> commit d6cd978f7e6b6f6895f8d0c4ce6e5d2c8e979afe
>     video: fbdev: fbmem: fix pointer reference to null device field
> 
> then I noticed that it was fixed already in another branch which led to this error:
> 
> Merging drm-misc/drm-misc-next... dim:
> dim: FAILURE: Could not merge drm-misc/drm-misc-next
> dim: See the section "Resolving Conflicts when Rebuilding drm-tip"
> dim: in the drm-tip.rst documentation for how to handle this situation.
> 
> I fixed it by reverting that patch above with this new commit in the drm-misc-next branch:
> 
> commit cabfa2bbe617ddf0a0cc4d01f72b584dae4939ad (HEAD -> drm-misc-next, drm-misc/for-linux-next, drm-misc/drm-misc-next)
> Author: Helge Deller <deller at gmx.de>
>     Revert "video: fbdev: fbmem: fix pointer reference to null device field"
> 
> My question (as "dim" newbie):
> Was that the right solution?

The patch wasn't really broken, so revert feels a bit silly. The hint was
to look at the documentation referenced by the error message - the issue
was only in rebuilding the integration tree:

https://drm.pages.freedesktop.org/maintainer-tools/drm-tip.html#resolving-conflicts-when-rebuilding-drm-tip

This should cover you even for really rare conflict situations.

> Is there a possibility to drop those two patches from the drm-misc-next branch before it gets pushed upstream?

It's a shared tree, mistakes are forever. The only time we did a forced
push ever is when someone managed to push their local pile of hacks or
something, and we're catching those pretty well now with a server-side
test to make sure you're using dim to push.

It's also no big deal, and next time you get a conflict just resolve it
in drm-tip per the docs and it's all fine.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch