The Mesa 3D Graphics Library

Submitting patches

Basic guidelines

Patch formatting

Testing Patches

It should go without saying that patches must be tested. In general, do whatever testing is prudent.

You should always run the Mesa test suite before submitting patches. The test suite can be run using the 'make check' command. All tests must pass before patches will be accepted, this may mean you have to update the tests themselves.

Whenever possible and applicable, test the patch with Piglit and/or dEQP to check for regressions.

Mailing Patches

Patches should be sent to the mesa-dev mailing list for review: mesa-dev@lists.freedesktop.org. When submitting a patch make sure to use git send-email rather than attaching patches to emails. Sending patches as attachments prevents people from being able to provide in-line review comments.

When submitting follow-up patches you can use --in-reply-to to make v2, v3, etc patches show up as replies to the originals. This usually works well when you're sending out updates to individual patches (as opposed to re-sending the whole series). Using --in-reply-to makes it harder for reviewers to accidentally review old patches.

When submitting follow-up patches you should also login to patchwork and change the state of your old patches to Superseded.

Reviewing Patches

When you've reviewed a patch on the mailing list, please be unambiguous about your review. That is, state either

    Reviewed-by: Joe Hacker <jhacker@foo.com>
or
    Acked-by: Joe Hacker <jhacker@foo.com>
Rather than saying just "LGTM" or "Seems OK".

If small changes are suggested, it's OK to say something like:

   With the above fixes, Reviewed-by: Joe Hacker <jhacker@foo.com>
which tells the patch author that the patch can be committed, as long as the issues are resolved first.

Nominating a commit for a stable branch

If you want a commit to be applied to a stable branch, you should add an appropriate note to the commit message.

Here are some examples of such a note:

Simply adding the CC to the mesa-stable list address is adequate to nominate the commit for the most-recently-created stable branch. It is only necessary to specify a specific branch name, (such as "9.2 10.0" or "10.0" in the examples above), if you want to nominate the commit for an older stable branch. And, as in these examples, you can nominate the commit for the older branch in addition to the more recent branch, or nominate the commit exclusively for the older branch. This "CC" syntax for patch nomination will cause patches to automatically be copied to the mesa-stable@ mailing list when you use "git send-email" to send patches to the mesa-dev@ mailing list. Also, if you realize that a commit should be nominated for the stable branch after it has already been committed, you can send a note directly to the mesa-stable@lists.freedesktop.org where the Mesa stable-branch maintainers will receive it. Be sure to mention the commit ID of the commit of interest (as it appears in the mesa master branch). The latest set of patches that have been nominated, accepted, or rejected for the upcoming stable release can always be seen on the Mesa Stable Queue page.

Criteria for accepting patches to the stable branch

Mesa has a designated release manager for each stable branch, and the release manager is the only developer that should be pushing changes to these branches. Everyone else should simply nominate patches using the mechanism described above. The stable-release manager will work with the list of nominated patches, and for each patch that meets the crtieria below will cherry-pick the patch with: git cherry-pick -x <commit>. The -x option is important so that the picked patch references the comit ID of the original patch. The stable-release manager may at times need to force-push changes to the stable branches, for example, to drop a previously-picked patch that was later identified as causing a regression). These force-pushes may cause changes to be lost from the stable branch if developers push things directly. Consider yourself warned. The stable-release manager is also given broad discretion in rejecting patches that have been nominated for the stable branch. The most basic rule is that the stable branch is for bug fixes only, (no new features, no regressions). Here is a non-exhaustive list of some reasons that a patch may be rejected: