A patch that is suitable for merging has to meet a number of formal requirements:
- it must be a git-formatted patch
- it must be signed off
- it must have a single-line subject (less than 72 characters)
- it must have a meaningful commit message
- The driver must pass make check
Any patch that meets these requirements can be sent to the linuxwacom-devel mailing list for review and merging. Below is more information on each of these three points.
Signing off your patch
A Signed-off-by: tag in your commit message certifies that you wrote it or otherwise have the right to pass it on as a open-source patch. For more information on this tag see the kernel's Documentation/SubmittingPatches guidelines.
Commit message format
The commit message format follows the following style:
One line summary less than 72 characters (a single blank line) A multi-line or multi-paragraph message describing the change in more detail and, most of all, describes your motivation for this patch. If you want to, you can include compiler output or statistics here too.
As always when coding, common sense is the most important rule and there are patches where a single line is enough or other rules apply. The goal of a commit message is always to make others quickly aware of your motivation and what you did so they can review the code with this in mind.
Submitting and review
Once submitted, it may take several days until a review comes in. In the best case, your patch went straight in. Many patches however need to be re-done before they are merged. Don't take it badly, even the maintainers of the driver regularly re-do the patches after review on the list. The main goal is to have an easy to understand, bug-free, maintainable codebase.
If you have to re-submit a patch, please state that this is a new version of a previous patch and list the differences to the previous version so reviewers can concentrate on that. The best space for this is after the -- in the patch file. The part there is automatically removed when applying the patch. And example is
[PATCH v2] the meaningful subject line most likely same summary as before but may be extended or changed. either way, still a useful summary. Signed-off-by: Wile E. Coyote <email@example.com> --- Changes to previous version: - fixed spelling of typo - changed the world, is now flat again - removed universe, world is center now geography/world.c | 5000 ++++--- geography/universe.c | 5000 ------- [...]