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en:developers:documentation:submittingpatches [2017/08/03 04:47]
Kalle Valo Add "Commit log does not answer "Why?""
en:developers:documentation:submittingpatches [2021/02/12 08:22] (current)
Johannes Berg
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   * [[en/​users/​drivers/​ath10k/​submittingpatches|ath10k]]   * [[en/​users/​drivers/​ath10k/​submittingpatches|ath10k]]
 +  * [[en/​users/​drivers/​ath11k/​submittingpatches|ath11k]]
 ===== Checking state of patches from patchwork ===== ===== Checking state of patches from patchwork =====
  
-All wireless patches are tracked in [[https://​patchwork.kernel.org/​project/​linux-wireless/​list/​|linux-wireless patchwork project]] ​(only exception being ath10k which has its own [[https://​patchwork.kernel.org/​project/​ath10k/​list/?​state=*|ath10k patchwork project]]). From patchwork you can check the state of the patch and to whom it is assigned. Here's a quick link to see all the patches, no matter what's the state:+All wireless patches are tracked in [[https://​patchwork.kernel.org/​project/​linux-wireless/​list/​|linux-wireless patchwork project]]. From patchwork you can check the state of the patch and to whom it is assigned. Here's a quick link to see all the patches, no matter what's the state:
  
 [[https://​patchwork.kernel.org/​project/​linux-wireless/​list/?​state=*]] [[https://​patchwork.kernel.org/​project/​linux-wireless/​list/?​state=*]]
  
-Always avoid contacting maintainers directly, they get way too much email already. Instead use the link above to find your patch and see the status. Only in last resort contact the maintainers,​ and do that by replying to your own patch and ask for status.+Always avoid contacting maintainers directly, they get way too much email already. Instead use the link above to find your patch and see the status. Only in last resort contact the maintainers,​ and do that by replying to your own patch and ask for status. ​Do not top post!
  
 Different patchwork states and their meanings: Different patchwork states and their meanings:
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 ===== Subject ===== ===== Subject =====
  
-If what you are sending is a patch you can use a subject as follows: ​+If what you are sending is a patch you should ​use a subject as follows: ​
  
  
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 If your patch is just a proposal you can mark the patch as RFC in the subject: ​ If your patch is just a proposal you can mark the patch as RFC in the subject: ​
  
-<​code>​[RFC] subsystem: a new way to do foo</​code>​+<​code>​[RFC] subsystem: ​add a new way to do foo</​code>​
  
 If you need to make changes to the patch add a version number inside the brackets: If you need to make changes to the patch add a version number inside the brackets:
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 If a patch in a bigger patchset changes resubmit the whole patchset, even the patches which have not changes. The maintainers look at patchsets as a complete unit, usually they do not want to take patches individually from a patchset. If a patch in a bigger patchset changes resubmit the whole patchset, even the patches which have not changes. The maintainers look at patchsets as a complete unit, usually they do not want to take patches individually from a patchset.
 +
 +Subject lines, like commit messages (see below) should be written in imperative voice ("fix foo and optimize bar"), not in any other way such as past tense ("​fixed foo and optimized bar").
 +
 +===== Commit Messages =====
 +
 +Please write commit messages, like mentioned for the subject above, in imperative voice.
 +
 +Commit messages should describe
 +  * why a change was made,
 +  * how it achieves its stated goal, and,
 +  * if applicable, other considerations such as
 +    * alternatives that were considered,
 +    * implications on other code,
 +    * possible security implications,​
 +    * etc.
 +
 +If you find yourself listing out a number of changes in the commit message as a bulleted list or similar, consider splitting up the patch into discrete changes that each do one thing. Similarly, if one of the additional considerations is refactoring,​ try to shift that into a separate patch.
 +
 +===== Tree labels =====
 +
 +Labeling patches with what tree the patch should go to helps maintainers to prioritise and sort patches and avoids unnecessary emails, which saves everyone time and speeds up patch review. Here are some tips how to label wireless patches.
 +
 +If you want to target your patch to a specific release (for example that the patch should go -rc release not -next) you can inform the maintainer by adding the release number inside the PATCH brackets:
 + 
 +<​code>​[PATCH 4.20] subsystem: fix foo</​code>​
 +
 +If you want to make it clear to the maintainer that the patch should NOT go to -rc release but to -next instead you can add "​-next"​ to PATCH brackets:
 +
 +<​code>​[PATCH -next] subsystem: fix foo</​code>​
 +
 +Alternatively you can specify the exact tree you are targetting by adding the name of the git tree inside PATCH brackets:
 +
 +<​code>​[PATCH mac80211] mac80211: fix foo
 +[PATCH mac80211-next] mac80211: implement very-cool-feature
 +[PATCH wireless-drivers] ath10k: fix foo
 +[PATCH wireless-drivers-next] ath10k: implement awesome-feature
 +</​code>​
 +
  
 ===== Sending large patches or multiple patches ===== ===== Sending large patches or multiple patches =====
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 ===== Format of patches ===== ===== Format of patches =====
  
-We prefer patches to be inline-text at the end of the body of the e-mail. ​You can use git-diff or the like to generate ​the patch. Additionally note that we prefer to apply patches with -p1. A header as follows is then acceptable: ​+We prefer patches to be inline-text at the end of the body of the e-mail. ​It's strongly recommended to use git-format-patch and git-send-email tools to submit patches as they use the correct format automatically. Additionally note that we prefer to apply patches with git-am (using the -p1 diff format). A header as follows is then acceptable: ​
  
  
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 Please also read the [[https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html|official Linux SubmittingPatches]] documentation,​ especially the **[[https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html#​sign-your-work-the-developer-s-certificate-of-origin|Developer'​s Certificate of Origin]]**. Do not submit patches unless you have read, understood and agreed to the certificate. ​ Please also read the [[https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html|official Linux SubmittingPatches]] documentation,​ especially the **[[https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html#​sign-your-work-the-developer-s-certificate-of-origin|Developer'​s Certificate of Origin]]**. Do not submit patches unless you have read, understood and agreed to the certificate. ​
  
 +
 +===== New driver =====
 +
 +For submitting a new wireless driver the requirements are:
 +
 +  * follow [[https://​www.kernel.org/​doc/​html/​latest/​process/​coding-style.html|Linux kernel coding style]]
 +  * use [[https://​www.kernel.org/​doc/​html/​latest/​process/​license-rules.html|SPDX tags]]
 +  * use either cfg80211 or mac80211, depending on the firmware architecture (no custom 802.11 stack in the driver)
 +  * have firmware images submitted for [[https://​git.kernel.org/​pub/​scm/​linux/​kernel/​git/​firmware/​linux-firmware.git/​|linux-firmware]] with an acceptable license allowing redistribution
 +  * document Device Tree usage in [[https://​www.kernel.org/​doc/​html/​latest/​devicetree/​bindings/​submitting-patches.html|devicetree bindings]] and review them with DT maintainers
 +  * in the commit log/cover letter provide an overview of the driver
 +    * what hardware the driver supports
 +    * what features are supported (client, AP, mesh modes etc)
 +  * for review submit the driver as one file per patch, to make it easier for the reviewers
 +    * example: https://​lore.kernel.org/​linux-wireless/​20200623110000.31559-1-ajay.kathat@microchip.com/​
 +  * final commit (after the review) will be one big patch
 +    * for staging drivers the final patch will be just a small patch moving the driver, example: https://​git.kernel.org/​linus/​5625f965d764
 +
 +There'​s also a list of [[https://​git.kernel.org/​pub/​scm/​linux/​kernel/​git/​torvalds/​linux.git/​tree/​LICENSES/​preferred|preferred licenses]] available.
  
 ===== Examples of a patches ===== ===== Examples of a patches =====
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 ==== Changelog missing ==== ==== Changelog missing ====
  
-When sending a new version of a patch or patchset you should **always** add a changelog so that maintainer can easily what has changed.+When sending a new version of a patch or patchset you should **always** add a changelog so that maintainer can easily ​see what has changed.
  
 If you have just one patch you can add the changelog after the ''​%%---%%''​ (three dashes) line. If you have just one patch you can add the changelog after the ''​%%---%%''​ (three dashes) line.
  
-If you have multiples patches (called a patchset) add the changelog to the cover letter. You can create the cover letter with switch ''​--cover-letter'':​+If you have multiples patches (called a patchset) add the changelog to the cover letter. You can create the cover letter with the switch ''​--cover-letter'':​
  
   git format-patch --subject-prefix="​PATCH v2" --cover-letter   git format-patch --subject-prefix="​PATCH v2" --cover-letter
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 ==== Signed-off-by missing ==== ==== Signed-off-by missing ====
  
-Read [[https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html#​sign-your-work-the-developer-s-certificate-of-origin|Developer'​s Certificate of Origin]] and add Signed-off-by ​to the commit log.+Read [[https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html#​sign-your-work-the-developer-s-certificate-of-origin|Developer'​s Certificate of Origin]]. Do not submit patches unless you have read, understood ​and agreed ​to the certificate. 
  
 ==== Format issues ==== ==== Format issues ====
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 commit log message header line text enclosed in parentheses and commit log message header line text enclosed in parentheses and
 double quotes with no line breaks whatsoever. double quotes with no line breaks whatsoever.
 +The fixes lines must be placed just above the signed-off-by lines.
  
 Example: Example:
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 The commit log needs to tell why you wrote the patch. If you fixed a bug give a short summary of the bug (can be a long one as well, of course) from user's point of view, and if there'​s a publically available bug report include a link to that. If you are fixing a warning from a compiler or a static checker add the warning from tool. Or if it's just code cleanup or fixing a theoretical issue, and does not have practical user visible changes, mention that also. The commit log needs to tell why you wrote the patch. If you fixed a bug give a short summary of the bug (can be a long one as well, of course) from user's point of view, and if there'​s a publically available bug report include a link to that. If you are fixing a warning from a compiler or a static checker add the warning from tool. Or if it's just code cleanup or fixing a theoretical issue, and does not have practical user visible changes, mention that also.
  
-===== More patch work references =====+==== Do not top post and edit your quotes ​==== 
 + 
 +Top posting makes following email threads hard to follow and also it makes use of patchwork more difficult, which gets the maintainers grumpy as you are making their work more difficult. So do not top post and instead edit your quotes properly. 
 + 
 +<​code>​A:​ Because it messes up the order in which people normally read text. 
 +Q: Why is top-posting such a bad thing? 
 +A: Top-posting. 
 +Q: What is the most annoying thing in e-mail? 
 + 
 +A: No. 
 +Q: Should I include quotations after my reply? 
 +</​code>​ 
 + 
 +More info: http://​www.idallen.com/​topposting.html 
 + 
 +==== Do not send HTML mail ==== 
 + 
 +linux-wireless mailing list drops all mail using HTML, so don't use it. 
 + 
 +==== Use RFC or RFT for patches not ready ==== 
 + 
 +If the patches are not yet ready to be applied by the maintainer, mark them as RFC (Request For Comments) or RFT (Request For Test). This way the maintainer can easily see that the patch should not be applied yet. This saves a lot of maintainer'​s time. 
 + 
 +==== Use Co-developed-by when multiple authors ​ ==== 
 + 
 +When a patch has multiple authors you should use Co-developed-by tag: 
 + 
 +https://​www.kernel.org/​doc/​html/​latest/​process/​submitting-patches.html#​when-to-use-acked-by-cc-and-co-developed-by 
 + 
 +==== Maximum of 7-12 patches per patchset ​ ==== 
 + 
 +If you want your patches reviewed smoothly submit maximum of 7-12 patches per patchset. If the patches are bigger don't send more than 7 patches. But if they smaller, or trivial patches, 12 patches is ok. But anything more than 12 patches and you will get reviewers grumpy (read: it takes longer to get your patches reviewed and applied). 
 + 
 +But you can submit multiple patchsets, just try to throttle it down to avoid bufferbloat in patchwork, for example you can send a new patchset every other day. And don't forget to document the dependencies in the cover letter ("this patchset depends on patchset B"). 
 + 
 +===== More references =====
  
 Here is a list of links to help you write better patches ​ Here is a list of links to help you write better patches ​
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   * [[http://​linux.yyz.us/​patch-format.html|http://​linux.yyz.us/​patch-format.html]] ​   * [[http://​linux.yyz.us/​patch-format.html|http://​linux.yyz.us/​patch-format.html]] ​
   * [[https://​www.ozlabs.org/​~akpm/​stuff/​tpp.txt|Andrew Morton'​s ''​The perfect patch''​]] ​   * [[https://​www.ozlabs.org/​~akpm/​stuff/​tpp.txt|Andrew Morton'​s ''​The perfect patch''​]] ​
 +  * [[http://​lkml.kernel.org/​r/​20171026223701.GA25649@bhelgaas-glaptop.roam.corp.google.com|Make Bjorn'​s life easier (and grease the path of your patch)]]
en/developers/documentation/submittingpatches.1501735663.txt.gz · Last modified: 2017/08/03 04:47 by Kalle Valo