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11 <h1>The Mesa
3D Graphics Library
</h1>
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17 <h1>Submitting patches
</h1>
21 <li><a href=
"#guidelines">Basic guidelines
</a>
22 <li><a href=
"#formatting">Patch formatting
</a>
23 <li><a href=
"#testing">Testing Patches
</a>
24 <li><a href=
"#submit">Submitting Patches
</a>
25 <li><a href=
"#reviewing">Reviewing Patches
</a>
26 <li><a href=
"#nominations">Nominating a commit for a stable branch
</a>
27 <li><a href=
"#criteria">Criteria for accepting patches to the stable branch
</a>
28 <li><a href=
"#backports">Sending backports for the stable branch
</a>
29 <li><a href=
"#gittips">Git tips
</a>
32 <h2 id=
"guidelines">Basic guidelines
</h2>
35 <li>Patches should not mix code changes with code formatting changes (except,
36 perhaps, in very trivial cases.)
37 <li>Code patches should follow Mesa
38 <a href=
"codingstyle.html" target=
"_parent">coding conventions
</a>.
39 <li>Whenever possible, patches should only affect individual Mesa/Gallium
41 <li>Patches should never introduce build breaks and should be bisectable (see
42 <code>git bisect
</code>.)
43 <li>Patches should be properly
<a href=
"#formatting">formatted
</a>.
44 <li>Patches should be sufficiently
<a href=
"#testing">tested
</a> before submitting.
45 <li>Patches should be
<a href=
"#submit">submitted
</a>
46 to
<a href=
"#mailing">mesa-dev
</a> or with
47 a
<a href=
"#merge-request">merge request
</a>
48 for
<a href=
"#reviewing">review
</a>.
52 <h2 id=
"formatting">Patch formatting
</h2>
55 <li>Lines should be limited to
75 characters or less so that git logs
56 displayed in
80-column terminals avoid line wrapping. Note that git
57 log uses
4 spaces of indentation (
4 +
75 < 80).
58 <li>The first line should be a short, concise summary of the change prefixed
59 with a module name. Examples:
61 mesa: Add support for querying GL_VERTEX_ATTRIB_ARRAY_LONG
63 gallium: add PIPE_CAP_DEVICE_RESET_STATUS_QUERY
65 i965: Fix missing type in local variable declaration.
67 <li>Subsequent patch comments should describe the change in more detail,
68 if needed. For example:
70 i965: Remove end-of-thread SEND alignment code.
72 This was present in Eric's initial implementation of the compaction code
73 for Sandybridge (commit
077d01b6). There is no documentation saying this
74 is necessary, and removing it causes no regressions in piglit on any
77 <li>A
"Signed-off-by:" line is not required, but not discouraged either.
78 <li>If a patch addresses a bugzilla issue, that should be noted in the
79 patch comment. For example:
81 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=
89689
83 <li>If a patch addresses a issue introduced with earlier commit, that should be
84 noted in the patch comment. For example:
86 Fixes: d7b3707c612
"util/disk_cache: use stat() to check if entry is a directory"
88 <li>If there have been several revisions to a patch during the review
89 process, they should be noted such as in this example:
91 st/mesa: add ARB_texture_stencil8 support (v4)
93 if we support stencil texturing, enable texture_stencil8
94 there is no requirement to support native S8 for this,
95 the texture can be converted to x24s8 fine.
97 v2: fold fixes from Marek in:
98 a) put S8 last in the list
99 b) fix renderable to always test for d/s renderable
100 fixup the texture case to use a stencil only format
101 for picking the format for the texture view.
102 v3: hit fallback for getteximage
103 v4: put s8 back in front, it shouldn't get picked now (Ilia)
105 <li>If someone tested your patch, document it with a line like this:
107 Tested-by: Joe Hacker
<jhacker@foo.com
>
109 <li>If the patch was reviewed (usually the case) or acked by someone,
110 that should be documented with:
112 Reviewed-by: Joe Hacker
<jhacker@foo.com
>
113 Acked-by: Joe Hacker
<jhacker@foo.com
>
115 <li>If sending later revision of a patch, add all the tags - ack, r-b,
116 Cc: mesa-stable and/or other. This provides reviewers with quick feedback if the
117 patch has already been reviewed.
118 <li>In order for your patch to reach the prospective reviewer easier/faster,
119 use the script scripts/get_reviewer.pl to get a list of individuals and include
122 Please use common sense and do
<strong>not
</strong> blindly add everyone.
125 $ scripts/get_reviewer.pl --help # to get the help screen
126 $ scripts/get_reviewer.pl -f src/egl/drivers/dri2/platform_android.c
127 Rob Herring
<robh@kernel.org
> (reviewer:ANDROID EGL SUPPORT,added_lines:
188/
700=
27%,removed_lines:
58/
283=
20%)
128 Tomasz Figa
<tfiga@chromium.org
> (reviewer:ANDROID EGL SUPPORT,authored:
12/
41=
29%,added_lines:
308/
700=
44%,removed_lines:
115/
283=
41%)
129 Emil Velikov
<emil.l.velikov@gmail.com
> (authored:
13/
41=
32%,removed_lines:
76/
283=
27%)
135 <h2 id=
"testing">Testing Patches
</h2>
138 It should go without saying that patches must be tested. In general,
139 do whatever testing is prudent.
143 You should always run the Mesa test suite before submitting patches.
144 The test suite can be run using the 'make check' command. All tests
145 must pass before patches will be accepted, this may mean you have
146 to update the tests themselves.
150 Whenever possible and applicable, test the patch with
151 <a href=
"https://piglit.freedesktop.org">Piglit
</a> and/or
152 <a href=
"https://android.googlesource.com/platform/external/deqp/">dEQP
</a>
153 to check for regressions.
157 As mentioned at the begining, patches should be bisectable.
158 A good way to test this is to make use of the `git rebase` command,
159 to run your tests on each commit. Assuming your branch is based off
160 <code>origin/master
</code>, you can run:
163 $ git rebase --interactive --exec
"make check" origin/master
166 replacing
<code>"make check"</code> with whatever other test you want to
171 <h2 id=
"submit">Submitting Patches
</h2>
174 Patches may be submitted to the Mesa project by
175 <a href=
"#mailing">email
</a> or with a
176 GitLab
<a href=
"#merge-request">merge request
</a>. To prevent
177 duplicate code review, only use one method to submit your changes.
180 <h3 id=
"mailing">Mailing Patches
</h3>
183 Patches may be sent to the mesa-dev mailing list for review:
184 <a href=
"https://lists.freedesktop.org/mailman/listinfo/mesa-dev">
185 mesa-dev@lists.freedesktop.org
</a>.
186 When submitting a patch make sure to use
187 <a href=
"https://git-scm.com/docs/git-send-email">git send-email
</a>
188 rather than attaching patches to emails. Sending patches as
189 attachments prevents people from being able to provide in-line review
194 When submitting follow-up patches you can use --in-reply-to to make v2, v3,
195 etc patches show up as replies to the originals. This usually works well
196 when you're sending out updates to individual patches (as opposed to
197 re-sending the whole series). Using --in-reply-to makes
198 it harder for reviewers to accidentally review old patches.
202 When submitting follow-up patches you should also login to
203 <a href=
"https://patchwork.freedesktop.org">patchwork
</a> and change the
204 state of your old patches to Superseded.
208 Some companies' mail server automatically append a legal disclaimer,
209 usually containing something along the lines of
"The information in this
210 email is confidential" and
"distribution is strictly prohibited".
<br/>
211 These legal notices prevent us from being able to accept your patch,
212 rendering the whole process pointless. Please make sure these are
213 disabled before sending your patches. (Note that you may need to contact
214 your email administrator for this.)
217 <h3 id=
"merge-request">GitLab Merge Requests
</h3>
220 <a href=
"https://gitlab.freedesktop.org/mesa/mesa">GitLab
</a> Merge
221 Requests (MR) can also be used to submit patches for Mesa.
225 If the MR may have interest for most of the Mesa community, you can
226 send an email to the mesa-dev email list including a link to the MR.
227 Don't send the patch to mesa-dev, just the MR link.
230 Add labels to your MR to help reviewers find it. For example:
232 <li>Mesa changes affecting all drivers: mesa
233 <li>Hardware vendor specific code: amd, intel, nvidia, ...
234 <li>Driver specific code: anvil, freedreno, i965, iris, radeonsi,
236 <li>Other tag examples: gallium, util
240 If you revise your patches based on code review and push an update
241 to your branch, you should maintain a
<strong>clean
</strong> history
242 in your patches. There should not be
"fixup" patches in the history.
243 The series should be buildable and functional after every commit
244 whenever you push the branch.
247 It is your responsibility to keep the MR alive and making progress,
248 as there are no guarantees that a Mesa dev will independently take
254 <li>Make changes and update your branch based on feedback
255 <li>Old, stale MR may be closed, but you can reopen it if you
256 still want to pursue the changes
257 <li>You should periodically check to see if your MR needs to be
259 <li>Make sure your MR is closed if your patches get pushed outside
261 <li>Please send MRs from a personal fork rather than from the main
262 Mesa repository, as it clutters it unnecessarily.
266 <h2 id=
"reviewing">Reviewing Patches
</h2>
269 To participate in code review, you should monitor the
270 <a href=
"https://lists.freedesktop.org/mailman/listinfo/mesa-dev">
271 mesa-dev
</a> email list and the GitLab
272 Mesa
<a href=
"https://gitlab.freedesktop.org/mesa/mesa/merge_requests">Merge
277 When you've reviewed a patch on the mailing list, please be unambiguous
278 about your review. That is, state either
281 Reviewed-by: Joe Hacker
<jhacker@foo.com
>
285 Acked-by: Joe Hacker
<jhacker@foo.com
>
288 Rather than saying just
"LGTM" or
"Seems OK".
292 If small changes are suggested, it's OK to say something like:
295 With the above fixes, Reviewed-by: Joe Hacker
<jhacker@foo.com
>
298 which tells the patch author that the patch can be committed, as long
299 as the issues are resolved first.
303 These Reviewed-by, Acked-by, and Tested-by tags should also be amended
304 into commits in a MR before it is merged.
308 When providing a Reviewed-by, Acked-by, or Tested-by tag in a gitlab MR,
309 enclose the tag in backticks:
312 `Reviewed-by: Joe Hacker
<jhacker@example.com
>`
</pre>
314 This is the markdown format for literal, and will prevent gitlab from hiding
315 the
< and
> symbols.
319 Review by non-experts is encouraged. Understanding how someone else
320 goes about solving a problem is a great way to learn your way around
321 the project. The submitter is expected to evaluate whether they have
322 an appropriate amount of review feedback from people who also
323 understand the code before merging their patches.
326 <h2 id=
"nominations">Nominating a commit for a stable branch
</h2>
329 There are three ways to nominate a patch for inclusion in the stable branch and
333 <li> By adding the Cc: mesa-stable@ tag as described below.
334 <li> Sending the commit ID (as seen in master branch) to the mesa-stable@ mailing list.
335 <li> Forwarding the patch from the mesa-dev@ mailing list.
339 Note: resending patch identical to one on mesa-dev@ or one that differs only
340 by the extra mesa-stable@ tag is
<strong>not
</strong> recommended.
343 If you are not the author of the original patch, please Cc: them in your
348 The current patch status can be observed in the
<a href=
"releasing.html#stagingbranch">staging branch
</a>.
351 <h3 id=
"thetag">The stable tag
</h3>
354 If you want a commit to be applied to a stable branch,
355 you should add an appropriate note to the commit message.
359 Here are some examples of such a note:
362 <li>CC:
<mesa-stable@lists.freedesktop.org
></li>
365 Simply adding the CC to the mesa-stable list address is adequate to nominate
366 the commit for all the active stable branches. If the commit is not applicable
367 for said branch the stable-release manager will reply stating so.
369 This
"CC" syntax for patch nomination will cause patches to automatically be
370 copied to the mesa-stable@ mailing list when you use
"git send-email" to send
371 patches to the mesa-dev@ mailing list. If you prefer using --suppress-cc that
372 won't have any negative effect on the patch nomination.
375 Note: by removing the tag [as the commit is pushed] the patch is
376 <strong>explicitly
</strong> rejected from inclusion in the stable branch(es).
378 Thus, drop the line
<strong>only
</strong> if you want to cancel the nomination.
381 Alternatively, if one uses the
"Fixes" tag as described in the
"Patch formatting"
382 section, it nominates a commit for all active stable branches that include the
383 commit that is referred to.
385 <h2 id=
"criteria">Criteria for accepting patches to the stable branch
</h2>
387 Mesa has a designated release manager for each stable branch, and the release
388 manager is the only developer that should be pushing changes to these branches.
389 Everyone else should nominate patches using the mechanism described above.
391 The following rules define which patches are accepted and which are not. The
392 stable-release manager is also given broad discretion in rejecting patches
393 that have been nominated.
396 <li>Patch must conform with the
<a href=
"#guidelines">Basic guidelines
</a></li>
398 <li>Patch must have landed in master first. In case where the original
399 patch is too large and/or otherwise contradicts with the rules set within, a
400 backport is appropriate.
</li>
402 <li>It must not introduce a regression - be that build or runtime wise.
404 Note: If the regression is due to faulty piglit/dEQP/CTS/other test the
405 latter must be fixed first. A reference to the offending test(s) and
406 respective fix(es) should be provided in the nominated patch.
</li>
408 <li>Patch cannot be larger than
100 lines.
</li>
410 <li>Patches that move code around with no functional change should be
413 <li>Patch must be a bug fix and not a new feature.
415 Note: An exception to this rule, are hardware-enabling
"features". For
416 example,
<a href=
"#backports">backports
</a> of new code to support a
417 newly-developed hardware product can be accepted if they can be reasonably
418 determined not to have effects on other hardware.
</li>
420 <li>Patch must be reviewed, For example, the commit message has Reviewed-by,
421 Signed-off-by, or Tested-by tags from someone but the author.
</li>
423 <li>Performance patches are considered only if they provide information
424 about the hardware, program in question and observed improvement. Use numbers
425 to represent your measurements.
</li>
428 If the patch complies with the rules it will be
429 <a href=
"releasing.html#pickntest">cherry-picked
</a>. Alternatively the release
430 manager will reply to the patch in question stating why the patch has been
431 rejected or would request a backport.
433 A summary of all the picked/rejected patches will be presented in the
434 <a href=
"releasing.html#prerelease">pre-release
</a> announcement.
436 The stable-release manager may at times need to force-push changes to the
437 stable branches, for example, to drop a previously-picked patch that was later
438 identified as causing a regression). These force-pushes may cause changes to
439 be lost from the stable branch if developers push things directly. Consider
442 <h2 id=
"backports">Sending backports for the stable branch
</h2>
443 By default merge conflicts are resolved by the stable-release manager. In which
444 case he/she should provide a comment about the changes required, alongside the
445 <code>Conflicts
</code> section. Summary of which will be provided in the
446 <a href=
"releasing.html#prerelease">pre-release
</a> announcement.
448 Developers are interested in sending backports are recommended to use either a
449 <code>[BACKPORT #branch]
</code> subject prefix or provides similar information
450 within the commit summary.
452 <h2 id=
"gittips">Git tips
</h2>
455 <li><code>git rebase -i ...
</code> is your friend. Don't be afraid to use it.
456 <li>Apply a fixup to commit FOO.
459 git commit --fixup=FOO
460 git rebase -i --autosquash ...
462 <li>Test for build breakage between patches e.g last
8 commits.
464 git rebase -i
--exec=
"make -j4" HEAD~
8
466 <li>Sets the default mailing address for your repo.
468 git config --local sendemail.to mesa-dev@lists.freedesktop.org
470 <li> Add version to subject line of patch series in this case for the last
8
471 commits before sending.
473 git send-email
--subject-prefix=
"PATCH v4" HEAD~
8
474 git send-email -v4 @~
8 # shorter version, inherited from git format-patch
476 <li> Configure git to use the get_reviewer.pl script interactively. Thus you
477 can avoid adding the world to the CC list.
479 git config sendemail.cccmd
"./scripts/get_reviewer.pl -i"