1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html lang="en"> 3<head> 4 <meta http-equiv="content-type" content="text/html; charset=utf-8"> 5 <title>Submitting patches</title> 6 <link rel="stylesheet" type="text/css" href="mesa.css"> 7</head> 8<body> 9 10<div class="header"> 11 <h1>The Mesa 3D Graphics Library</h1> 12</div> 13 14<iframe src="contents.html"></iframe> 15<div class="content"> 16 17<h1>Submitting patches</h1> 18 19 20<ul> 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="#mailing">Mailing 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> 30</ul> 31 32<h2 id="guidelines">Basic guidelines</h2> 33 34<ul> 35<li>Patches should not mix code changes with code formatting changes (except, 36perhaps, 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 effect individual Mesa/Gallium 40components. 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 submitted to <a href="#mailing">mesa-dev</a> 46for <a href="#reviewing">review</a> using <code>git send-email</code>. 47 48</ul> 49 50<h2 id="formatting">Patch formatting</h2> 51 52<ul> 53<li>Lines should be limited to 75 characters or less so that git logs 54displayed in 80-column terminals avoid line wrapping. Note that git 55log uses 4 spaces of indentation (4 + 75 < 80). 56<li>The first line should be a short, concise summary of the change prefixed 57with a module name. Examples: 58<pre> 59 mesa: Add support for querying GL_VERTEX_ATTRIB_ARRAY_LONG 60 61 gallium: add PIPE_CAP_DEVICE_RESET_STATUS_QUERY 62 63 i965: Fix missing type in local variable declaration. 64</pre> 65<li>Subsequent patch comments should describe the change in more detail, 66if needed. For example: 67<pre> 68 i965: Remove end-of-thread SEND alignment code. 69 70 This was present in Eric's initial implementation of the compaction code 71 for Sandybridge (commit 077d01b6). There is no documentation saying this 72 is necessary, and removing it causes no regressions in piglit on any 73 platform. 74</pre> 75<li>A "Signed-off-by:" line is not required, but not discouraged either. 76<li>If a patch addresses a bugzilla issue, that should be noted in the 77patch comment. For example: 78<pre> 79 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89689 80</pre> 81<li>If a patch addresses a issue introduced with earlier commit, that should be 82noted in the patch comment. For example: 83<pre> 84 Fixes: d7b3707c612 "util/disk_cache: use stat() to check if entry is a directory" 85</pre> 86<li>If there have been several revisions to a patch during the review 87process, they should be noted such as in this example: 88<pre> 89 st/mesa: add ARB_texture_stencil8 support (v4) 90 91 if we support stencil texturing, enable texture_stencil8 92 there is no requirement to support native S8 for this, 93 the texture can be converted to x24s8 fine. 94 95 v2: fold fixes from Marek in: 96 a) put S8 last in the list 97 b) fix renderable to always test for d/s renderable 98 fixup the texture case to use a stencil only format 99 for picking the format for the texture view. 100 v3: hit fallback for getteximage 101 v4: put s8 back in front, it shouldn't get picked now (Ilia) 102</pre> 103<li>If someone tested your patch, document it with a line like this: 104<pre> 105 Tested-by: Joe Hacker <jhacker@foo.com> 106</pre> 107<li>If the patch was reviewed (usually the case) or acked by someone, 108that should be documented with: 109<pre> 110 Reviewed-by: Joe Hacker <jhacker@foo.com> 111 Acked-by: Joe Hacker <jhacker@foo.com> 112</pre> 113<li>If sending later revision of a patch, add all the tags - ack, r-b, 114Cc: mesa-stable and/or other. This provides reviewers with quick feedback if the 115patch has already been reviewed. 116<li>In order for your patch to reach the prospective reviewer easier/faster, 117use the script scripts/get_reviewer.pl to get a list of individuals and include 118them in the CC list. 119<br> 120Please use common sense and do <strong>not</strong> blindly add everyone. 121<br> 122<pre> 123 $ scripts/get_reviewer.pl --help # to get the help screen 124 $ scripts/get_reviewer.pl -f src/egl/drivers/dri2/platform_android.c 125 Rob Herring <robh@kernel.org> (reviewer:ANDROID EGL SUPPORT,added_lines:188/700=27%,removed_lines:58/283=20%) 126 Tomasz Figa <tfiga@chromium.org> (reviewer:ANDROID EGL SUPPORT,authored:12/41=29%,added_lines:308/700=44%,removed_lines:115/283=41%) 127 Emil Velikov <emil.l.velikov@gmail.com> (authored:13/41=32%,removed_lines:76/283=27%) 128</pre> 129</ul> 130 131 132 133<h2 id="testing">Testing Patches</h2> 134 135<p> 136It should go without saying that patches must be tested. In general, 137do whatever testing is prudent. 138</p> 139 140<p> 141You should always run the Mesa test suite before submitting patches. 142The test suite can be run using the 'make check' command. All tests 143must pass before patches will be accepted, this may mean you have 144to update the tests themselves. 145</p> 146 147<p> 148Whenever possible and applicable, test the patch with 149<a href="https://piglit.freedesktop.org">Piglit</a> and/or 150<a href="https://android.googlesource.com/platform/external/deqp/">dEQP</a> 151to check for regressions. 152</p> 153 154<p> 155As mentioned at the begining, patches should be bisectable. 156A good way to test this is to make use of the `git rebase` command, 157to run your tests on each commit. Assuming your branch is based off 158<code>origin/master</code>, you can run: 159<pre> 160$ git rebase --interactive --exec "make check" origin/master 161</pre> 162replacing <code>"make check"</code> with whatever other test you want to 163run. 164</p> 165 166 167<h2 id="mailing">Mailing Patches</h2> 168 169<p> 170Patches should be sent to the mesa-dev mailing list for review: 171<a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev"> 172mesa-dev@lists.freedesktop.org</a>. 173When submitting a patch make sure to use 174<a href="https://git-scm.com/docs/git-send-email">git send-email</a> 175rather than attaching patches to emails. Sending patches as 176attachments prevents people from being able to provide in-line review 177comments. 178</p> 179 180<p> 181When submitting follow-up patches you can use --in-reply-to to make v2, v3, 182etc patches show up as replies to the originals. This usually works well 183when you're sending out updates to individual patches (as opposed to 184re-sending the whole series). Using --in-reply-to makes 185it harder for reviewers to accidentally review old patches. 186</p> 187 188<p> 189When submitting follow-up patches you should also login to 190<a href="https://patchwork.freedesktop.org">patchwork</a> and change the 191state of your old patches to Superseded. 192</p> 193 194<p> 195Some companies' mail server automatically append a legal disclaimer, 196usually containing something along the lines of "The information in this 197email is confidential" and "distribution is strictly prohibited".<br/> 198These legal notices prevent us from being able to accept your patch, 199rendering the whole process pointless. Please make sure these are 200disabled before sending your patches. (Note that you may need to contact 201your email administrator for this.) 202</p> 203 204<h2 id="reviewing">Reviewing Patches</h2> 205 206<p> 207When you've reviewed a patch on the mailing list, please be unambiguous 208about your review. That is, state either 209</p> 210<pre> 211 Reviewed-by: Joe Hacker <jhacker@foo.com> 212</pre> 213or 214<pre> 215 Acked-by: Joe Hacker <jhacker@foo.com> 216</pre> 217<p> 218Rather than saying just "LGTM" or "Seems OK". 219</p> 220 221<p> 222If small changes are suggested, it's OK to say something like: 223</p> 224<pre> 225 With the above fixes, Reviewed-by: Joe Hacker <jhacker@foo.com> 226</pre> 227<p> 228which tells the patch author that the patch can be committed, as long 229as the issues are resolved first. 230</p> 231 232 233<h2 id="nominations">Nominating a commit for a stable branch</h2> 234 235<p> 236There are three ways to nominate a patch for inclusion in the stable branch and 237release. 238</p> 239<ul> 240<li> By adding the Cc: mesa-stable@ tag as described below. 241<li> Sending the commit ID (as seen in master branch) to the mesa-stable@ mailing list. 242<li> Forwarding the patch from the mesa-dev@ mailing list. 243</li> 244</ul> 245<p> 246Note: resending patch identical to one on mesa-dev@ or one that differs only 247by the extra mesa-stable@ tag is <strong>not</strong> recommended. 248</p> 249 250 251<h3 id="thetag">The stable tag</h3> 252 253<p> 254If you want a commit to be applied to a stable branch, 255you should add an appropriate note to the commit message. 256</p> 257 258<p> 259Here are some examples of such a note: 260</p> 261<ul> 262 <li>CC: <mesa-stable@lists.freedesktop.org></li> 263</ul> 264 265Simply adding the CC to the mesa-stable list address is adequate to nominate 266the commit for all the active stable branches. If the commit is not applicable 267for said branch the stable-release manager will reply stating so. 268 269This "CC" syntax for patch nomination will cause patches to automatically be 270copied to the mesa-stable@ mailing list when you use "git send-email" to send 271patches to the mesa-dev@ mailing list. If you prefer using --suppress-cc that 272won't have any negative effect on the patch nomination. 273 274<p> 275Note: by removing the tag [as the commit is pushed] the patch is 276<strong>explicitly</strong> rejected from inclusion in the stable branch(es). 277<br> 278Thus, drop the line <strong>only</strong> if you want to cancel the nomination. 279</p> 280 281Alternatively, if one uses the "Fixes" tag as described in the "Patch formatting" 282section, it nominates a commit for all active stable branches that include the 283commit that is referred to. 284 285<h2 id="criteria">Criteria for accepting patches to the stable branch</h2> 286 287Mesa has a designated release manager for each stable branch, and the release 288manager is the only developer that should be pushing changes to these branches. 289Everyone else should nominate patches using the mechanism described above. 290 291The following rules define which patches are accepted and which are not. The 292stable-release manager is also given broad discretion in rejecting patches 293that have been nominated. 294 295<ul> 296 <li>Patch must conform with the <a href="#guidelines">Basic guidelines</a></li> 297 298 <li>Patch must have landed in master first. In case where the original 299 patch is too large and/or otherwise contradicts with the rules set within, a 300 backport is appropriate.</li> 301 302 <li>It must not introduce a regression - be that build or runtime wise. 303 304 Note: If the regression is due to faulty piglit/dEQP/CTS/other test the 305 latter must be fixed first. A reference to the offending test(s) and 306 respective fix(es) should be provided in the nominated patch.</li> 307 308 <li>Patch cannot be larger than 100 lines.</li> 309 310 <li>Patches that move code around with no functional change should be 311 rejected.</li> 312 313 <li>Patch must be a bug fix and not a new feature. 314 315 Note: An exception to this rule, are hardware-enabling "features". For 316 example, <a href="#backports">backports</a> of new code to support a 317 newly-developed hardware product can be accepted if they can be reasonably 318 determined not to have effects on other hardware.</li> 319 320 <li>Patch must be reviewed, For example, the commit message has Reviewed-by, 321 Signed-off-by, or Tested-by tags from someone but the author.</li> 322 323 <li>Performance patches are considered only if they provide information 324 about the hardware, program in question and observed improvement. Use numbers 325 to represent your measurements.</li> 326</ul> 327 328If the patch complies with the rules it will be 329<a href="releasing.html#pickntest">cherry-picked</a>. Alternatively the release 330manager will reply to the patch in question stating why the patch has been 331rejected or would request a backport. 332 333A summary of all the picked/rejected patches will be presented in the 334<a href="releasing.html#prerelease">pre-release</a> announcement. 335 336The stable-release manager may at times need to force-push changes to the 337stable branches, for example, to drop a previously-picked patch that was later 338identified as causing a regression). These force-pushes may cause changes to 339be lost from the stable branch if developers push things directly. Consider 340yourself warned. 341 342<h2 id="backports">Sending backports for the stable branch</h2> 343By default merge conflicts are resolved by the stable-release manager. In which 344case he/she should provide a comment about the changes required, alongside the 345<code>Conflicts</code> section. Summary of which will be provided in the 346<a href="releasing.html#prerelease">pre-release</a> announcement. 347<br> 348Developers are interested in sending backports are recommended to use either a 349<code>[BACKPORT #branch]</code> subject prefix or provides similar information 350within the commit summary. 351 352<h2 id="gittips">Git tips</h2> 353 354<ul> 355<li><code>git rebase -i ...</code> is your friend. Don't be afraid to use it. 356<li>Apply a fixup to commit FOO. 357<pre> 358 git add ... 359 git commit --fixup=FOO 360 git rebase -i --autosquash ... 361</pre> 362<li>Test for build breakage between patches e.g last 8 commits. 363<pre> 364 git rebase -i --exec="make -j4" HEAD~8 365</pre> 366<li>Sets the default mailing address for your repo. 367<pre> 368 git config --local sendemail.to mesa-dev@lists.freedesktop.org 369</pre> 370<li> Add version to subject line of patch series in this case for the last 8 371commits before sending. 372<pre> 373 git send-email --subject-prefix="PATCH v4" HEAD~8 374 git send-email -v4 @~8 # shorter version, inherited from git format-patch 375</pre> 376<li> Configure git to use the get_reviewer.pl script interactively. Thus you 377can avoid adding the world to the CC list. 378<pre> 379 git config sendemail.cccmd "./scripts/get_reviewer.pl -i" 380</pre> 381</ul> 382 383 384</div> 385</body> 386</html> 387