1 .. SPDX-License-Identifier: GPL-2.0+
2
3 =========================================
4 Automated testing of the DRM subsystem
5 =========================================
6
7 Introduction
8 ============
9
10 Making sure that changes to the core or drivers don't introduce regressions can
11 be very time-consuming when lots of different hardware configurations need to
12 be tested. Moreover, it isn't practical for each person interested in this
13 testing to have to acquire and maintain what can be a considerable amount of
14 hardware.
15
16 Also, it is desirable for developers to check for regressions in their code by
17 themselves, instead of relying on the maintainers to find them and then
18 reporting back.
19
20 There are facilities in gitlab.freedesktop.org to automatically test Mesa that
21 can be used as well for testing the DRM subsystem. This document explains how
22 people interested in testing it can use this shared infrastructure to save
23 quite some time and effort.
24
25
26 Relevant files
27 ==============
28
29 drivers/gpu/drm/ci/gitlab-ci.yml
30 --------------------------------
31
32 This is the root configuration file for GitLab CI. Among other less interesting
33 bits, it specifies the specific version of the scripts to be used. There are
34 some variables that can be modified to change the behavior of the pipeline:
35
36 DRM_CI_PROJECT_PATH
37 Repository that contains the Mesa software infrastructure for CI
38
39 DRM_CI_COMMIT_SHA
40 A particular revision to use from that repository
41
42 UPSTREAM_REPO
43 URL to git repository containing the target branch
44
45 TARGET_BRANCH
46 Branch to which this branch is to be merged into
47
48 IGT_VERSION
49 Revision of igt-gpu-tools being used, from
50 https://gitlab.freedesktop.org/drm/igt-gpu-tools
51
52 drivers/gpu/drm/ci/testlist.txt
53 -------------------------------
54
55 IGT tests to be run on all drivers (unless mentioned in a driver's \*-skips.txt
56 file, see below).
57
58 drivers/gpu/drm/ci/${DRIVER_NAME}-${HW_REVISION}-fails.txt
59 ----------------------------------------------------------
60
61 Lists the known failures for a given driver on a specific hardware revision.
62
63 drivers/gpu/drm/ci/${DRIVER_NAME}-${HW_REVISION}-flakes.txt
64 -----------------------------------------------------------
65
66 Lists the tests that for a given driver on a specific hardware revision are
67 known to behave unreliably. These tests won't cause a job to fail regardless of
68 the result. They will still be run.
69
70 Each new flake entry must be associated with a link to the email reporting the
71 bug to the author of the affected driver, the board name or Device Tree name of
72 the board, the first kernel version affected, the IGT version used for tests,
73 and an approximation of the failure rate.
74
75 They should be provided under the following format::
76
77 # Bug Report: $LORE_OR_PATCHWORK_URL
78 # Board Name: broken-board.dtb
79 # Linux Version: 6.6-rc1
80 # IGT Version: 1.28-gd2af13d9f
81 # Failure Rate: 100
82 flaky-test
83
84 drivers/gpu/drm/ci/${DRIVER_NAME}-${HW_REVISION}-skips.txt
85 -----------------------------------------------------------
86
87 Lists the tests that won't be run for a given driver on a specific hardware
88 revision. These are usually tests that interfere with the running of the test
89 list due to hanging the machine, causing OOM, taking too long, etc.
90
91
92 How to enable automated testing on your tree
93 ============================================
94
95 1. Create a Linux tree in https://gitlab.freedesktop.org/ if you don't have one
96 yet
97
98 2. In your kernel repo's configuration (eg.
99 https://gitlab.freedesktop.org/janedoe/linux/-/settings/ci_cd), change the
100 CI/CD configuration file from .gitlab-ci.yml to
101 drivers/gpu/drm/ci/gitlab-ci.yml.
102
103 3. Request to be added to the drm/ci-ok group so that your user has the
104 necessary privileges to run the CI on https://gitlab.freedesktop.org/drm/ci-ok
105
106 4. Next time you push to this repository, you will see a CI pipeline being
107 created (eg. https://gitlab.freedesktop.org/janedoe/linux/-/pipelines)
108
109 5. The various jobs will be run and when the pipeline is finished, all jobs
110 should be green unless a regression has been found.
111
112
113 How to update test expectations
114 ===============================
115
116 If your changes to the code fix any tests, you will have to remove one or more
117 lines from one or more of the files in
118 drivers/gpu/drm/ci/${DRIVER_NAME}_*_fails.txt, for each of the test platforms
119 affected by the change.
120
121
122 How to expand coverage
123 ======================
124
125 If your code changes make it possible to run more tests (by solving reliability
126 issues, for example), you can remove tests from the flakes and/or skips lists,
127 and then the expected results if there are any known failures.
128
129 If there is a need for updating the version of IGT being used (maybe you have
130 added more tests to it), update the IGT_VERSION variable at the top of the
131 gitlab-ci.yml file.
132
133
134 How to test your changes to the scripts
135 =======================================
136
137 For testing changes to the scripts in the drm-ci repo, change the
138 DRM_CI_PROJECT_PATH and DRM_CI_COMMIT_SHA variables in
139 drivers/gpu/drm/ci/gitlab-ci.yml to match your fork of the project (eg.
140 janedoe/drm-ci). This fork needs to be in https://gitlab.freedesktop.org/.
141
142
143 How to incorporate external fixes in your testing
144 =================================================
145
146 Often, regressions in other trees will prevent testing changes local to the
147 tree under test. These fixes will be automatically merged in during the build
148 jobs from a branch in the target tree that is named as
149 ${TARGET_BRANCH}-external-fixes.
150
151 If the pipeline is not in a merge request and a branch with the same name
152 exists in the local tree, commits from that branch will be merged in as well.
153
154
155 How to deal with automated testing labs that may be down
156 ========================================================
157
158 If a hardware farm is down and thus causing pipelines to fail that would
159 otherwise pass, one can disable all jobs that would be submitted to that farm
160 by editing the file at
161 https://gitlab.freedesktop.org/gfx-ci/lab-status/-/blob/main/lab-status.yml.
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