1# How do I submit patches to Android Common Kernels 2 31. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. 4 These patches will be merged automatically in the corresponding common kernels. If the patch is already 5 in upstream Linux, post a backport of the patch that conforms to the patch requirements below. 6 - Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux, 7additions of `EXPORT_SYMBOL_GPL()` require an in-tree modular driver that uses the symbol -- so include 8the new driver or changes to an existing driver in the same patchset as the export. 9 - When sending patches upstream, the commit message must contain a clear case for why the patch 10is needed and beneficial to the community. Enabling out-of-tree drivers or functionality is not 11not a persuasive case. 12 132. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are 14 fixing an Android-specific bug, these are very unlikely to be accepted unless they have been 15 coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the 16 patch requirements below. 17 18# Common Kernel patch requirements 19 20- All patches must conform to the Linux kernel coding standards and pass `script/checkpatch.pl` 21- Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures 22(see https://source.android.com/setup/build/building-kernels) 23- If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: 24`UPSTREAM:`, `BACKPORT:`, `FROMGIT:`, `FROMLIST:`, or `ANDROID:`. 25- All patches must have a `Change-Id:` tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html) 26- If an Android bug has been assigned, there must be a `Bug:` tag. 27- All patches must have a `Signed-off-by:` tag by the author and the submitter 28 29Additional requirements are listed below based on patch type 30 31## Requirements for backports from mainline Linux: `UPSTREAM:`, `BACKPORT:` 32 33- If the patch is a cherry-pick from Linux mainline with no changes at all 34 - tag the patch subject with `UPSTREAM:`. 35 - add upstream commit information with a `(cherry picked from commit ...)` line 36 - Example: 37 - if the upstream commit message is 38``` 39 important patch from upstream 40 41 This is the detailed description of the important patch 42 43 Signed-off-by: Fred Jones <fred.jones@foo.org> 44``` 45>- then Joe Smith would upload the patch for the common kernel as 46``` 47 UPSTREAM: important patch from upstream 48 49 This is the detailed description of the important patch 50 51 Signed-off-by: Fred Jones <fred.jones@foo.org> 52 53 Bug: 135791357 54 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 55 (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1) 56 Signed-off-by: Joe Smith <joe.smith@foo.org> 57``` 58 59- If the patch requires any changes from the upstream version, tag the patch with `BACKPORT:` 60instead of `UPSTREAM:`. 61 - use the same tags as `UPSTREAM:` 62 - add comments about the changes under the `(cherry picked from commit ...)` line 63 - Example: 64``` 65 BACKPORT: important patch from upstream 66 67 This is the detailed description of the important patch 68 69 Signed-off-by: Fred Jones <fred.jones@foo.org> 70 71 Bug: 135791357 72 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 73 (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1) 74 [joe: Resolved minor conflict in drivers/foo/bar.c ] 75 Signed-off-by: Joe Smith <joe.smith@foo.org> 76``` 77 78## Requirements for other backports: `FROMGIT:`, `FROMLIST:`, 79 80- If the patch has been merged into an upstream maintainer tree, but has not yet 81been merged into Linux mainline 82 - tag the patch subject with `FROMGIT:` 83 - add info on where the patch came from as `(cherry picked from commit <sha1> <repo> <branch>)`. This 84must be a stable maintainer branch (not rebased, so don't use `linux-next` for example). 85 - if changes were required, use `BACKPORT: FROMGIT:` 86 - Example: 87 - if the commit message in the maintainer tree is 88``` 89 important patch from upstream 90 91 This is the detailed description of the important patch 92 93 Signed-off-by: Fred Jones <fred.jones@foo.org> 94``` 95>- then Joe Smith would upload the patch for the common kernel as 96``` 97 FROMGIT: important patch from upstream 98 99 This is the detailed description of the important patch 100 101 Signed-off-by: Fred Jones <fred.jones@foo.org> 102 103 Bug: 135791357 104 (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace 105 https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch) 106 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 107 Signed-off-by: Joe Smith <joe.smith@foo.org> 108``` 109 110 111- If the patch has been submitted to LKML, but not accepted into any maintainer tree 112 - tag the patch subject with `FROMLIST:` 113 - add a `Link:` tag with a link to the submittal on lore.kernel.org 114 - add a `Bug:` tag with the Android bug (required for patches not accepted into 115a maintainer tree) 116 - if changes were required, use `BACKPORT: FROMLIST:` 117 - Example: 118``` 119 FROMLIST: important patch from upstream 120 121 This is the detailed description of the important patch 122 123 Signed-off-by: Fred Jones <fred.jones@foo.org> 124 125 Bug: 135791357 126 Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/ 127 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 128 Signed-off-by: Joe Smith <joe.smith@foo.org> 129``` 130 131## Requirements for Android-specific patches: `ANDROID:` 132 133- If the patch is fixing a bug to Android-specific code 134 - tag the patch subject with `ANDROID:` 135 - add a `Fixes:` tag that cites the patch with the bug 136 - Example: 137``` 138 ANDROID: fix android-specific bug in foobar.c 139 140 This is the detailed description of the important fix 141 142 Fixes: 1234abcd2468 ("foobar: add cool feature") 143 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 144 Signed-off-by: Joe Smith <joe.smith@foo.org> 145``` 146 147- If the patch is a new feature 148 - tag the patch subject with `ANDROID:` 149 - add a `Bug:` tag with the Android bug (required for android-specific features) 150 151