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CONTRIBUTING

Patches to igt-gpu-tools are very much welcome, we really want this to be the universal set of low-level tools and testcases for kernel graphics drivers on Linux and similar platforms. So please bring on porting patches, bugfixes, improvements for documentation and new tools and testcases.

The Code

  • The code should follow kernel coding style: https://www.kernel.org/doc/html/latest/process/coding-style.html

  • Testcases (subtests) have to use minus signs (-) as a word separator. The generated documentation contains glossary of commonly used terms.

  • All new test have to be described using igt_describe() family of functions. The description should contain the spirit of the test (what is the general idea behind the test) and not the letter (C to English translation of the test). Refer to igt_describe() documentation for more details.

  • The generated documentation contains explanation of magic control blocks like igt_subtest and igt_fixture. Please make sure that you understand their roles and limitation before using/altering them.

  • Also please make full use of all the helpers and convenience macros provided by the igt library. The semantic patch lib/igt.cocci can help with more automatic conversions.

  • Tests that use kernel interfaces (uapi, sysfs, or even debugfs) that become deprecated in favour of new interfaces should have fallbacks to the deprecated interfaces if the new stuff is not present in the running kernel. The same IGT version can be used to test the tip of development along with stable kernel releases that way.

IGT libraries

  • Tests and benchmarks are the main usage of IGT libraries, so they could use test specific macros/functions, for example igt_assert, igt_require, igt_skip, igt_info or igt_debug.

  • New library function could be written when it will have at least two different users, for example if it could be used by two or more tests. In some cases single user can be accepted, when it is very likely it will be used in future.

  • In a new library function(): if it uses some of the macros igt_assert/igt_require/igt_skip then consider to write also __function() with the same functionality but without those macros.

  • Libraries and igt_runner Runner should not use lib functions. It is crucial for CI runs so using libraries puts a risk of bringing changes meant for tests which in turn could break runner. Note: You will find places where igt_runner uses lib functions - this will be on ToDo list to be fixed.

  • Libraries and tools/ Give some thought if you are planning to use IGT lib code in tools, some IGT lib functions might not be appropriate in tools. For example, any abnormal condition should be simply reported by printf or fprintf to stdout/stderr and then tool should exit gracefully.

Sending Patches

  • igt-gpu-tools is MIT licensed and we require contributions to follow the developer's certificate of origin: http://developercertificate.org/

  • Please submit patches formatted with git send-email/git format-patch or equivalent to:

    Development mailing list for IGT GPU Tools igt-dev@lists.freedesktop.org

For patches affecting the driver directly please "cc" the appropriate driver mailing list and make sure you are using:

  --subject-prefix="PATCH i-g-t"

so IGT patches are easily identified in the massive amount mails on driver's mailing list. To ensure this is always done, meson.sh (and autogen.sh) will run:

  git config format.subjectprefix "PATCH i-g-t"

on its first invocation.

  • If you plan to contribute regularly, please subscribe to igt-dev mailinglist: https://lists.freedesktop.org/mailman/listinfo/igt-dev When you are not subscribed, please note that your contribution will take more time to reach to mailing list. You could find out if it was delivered or what is a testing status of your patches at page: https://patchwork.freedesktop.org/project/igt/series/ and also on https://lore.kernel.org/igt-dev/

  • Place relevant prefix in subject, for example when your change is in one testfile, use its name without '.c' nor '.h' suffix, like: tests/simple_test: short description Consider sending cover letter with your patch, so if you decide to change subject it can still be linked into same patchseries on patchwork.

  • Look into some guides from Linux and Open Source community: https://kernelnewbies.org/PatchPhilosophy https://www.kernel.org/doc/html/latest/process/submitting-patches.html https://www.kernel.org/doc/html/latest/process/submit-checklist.html

  • Patches need to be reviewed on the mailing list. Exceptions only apply for testcases and tooling for drivers with just a single contributor (e.g. vc4). In this case patches must still be submitted to the mailing list first. Testcase should preferably be cross-reviewed by the same people who write and review the kernel feature itself.

  • When patches from new contributors (without commit access) are stuck, for anything related to the regular releases, issues with packaging and integrating platform support or any other igt-gpu-tools issues, please contact one of the maintainers (listed in the MAINTAINERS file) and cc the igt-dev mailing list.

  • Before sending use Linux kernel script 'checkpatch.pl' for checking your patchset. You could ignore some of them like 'line too long' or 'typedef' but most of the time its log is accurate. Useful options you could use: --emacs --strict --show-types --max-line-length=100 \ --ignore=BIT_MACRO,SPLIT_STRING,LONG_LINE_STRING,BOOL_MEMBER

  • Changes to the testcases are automatically tested. Take the results into account before merging. Please also reply to CI failures if you think they are unrelated, add also to Cc CI e-mail which is present in message. This can help our bug-filing team. When replying, you can cut a message after 'Known bugs' to keep it in reasonable size.

Commit Rights

Commit rights will be granted to anyone who requests them and fulfills the below criteria:

  • Submitted a few (5-10 as a rule of thumb) non-trivial (not just simple spelling fixes and whitespace adjustment) patches that have been merged already.

  • Are actively participating on discussions about their work (on the mailing list or IRC). This should not be interpreted as a requirement to review other peoples patches but just make sure that patch submission isn't one-way communication. Cross-review is still highly encouraged.

  • Will be regularly contributing further patches. This includes regular contributors to other parts of the open source graphics stack who only do the oddball rare patch within igt itself.

  • Agrees to use their commit rights in accordance with the documented merge criteria, tools, and processes.

Create a gitlab account at https://gitlab.freedesktop.org/ and apply for access to the IGT gitlab project, http://gitlab.freedesktop.org/drm/igt-gpu-tools and please ping the maintainers if your request is stuck.

Committers are encouraged to request their commit rights get removed when they no longer contribute to the project. Commit rights will be reinstated when they come back to the project.

Maintainers and committers should encourage contributors to request commit rights, especially junior contributors tend to underestimate their skills.

Code of Conduct

Please be aware the fd.o Code of Conduct also applies to igt:

https://www.freedesktop.org/wiki/CodeOfConduct/

See the MAINTAINERS file for contact details of the igt maintainers.

Abuse of commit rights, like engaging in commit fights or willfully pushing patches that violate the documented merge criteria, will also be handled through the Code of Conduct enforcement process.

Happy hacking!