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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
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+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+Test Style and Nomenclature
+===========================
+
+To make finding, writing, and using KUnit tests as simple as possible, it is
+strongly encouraged that they are named and written according to the guidelines
+below. While it is possible to write KUnit tests which do not follow these rules,
+they may break some tooling, may conflict with other tests, and may not be run
+automatically by testing systems.
+
+It is recommended that you only deviate from these guidelines when:
+
+1. Porting tests to KUnit which are already known with an existing name.
+2. Writing tests which would cause serious problems if automatically run. For
+ example, non-deterministically producing false positives or negatives, or
+ taking a long time to run.
+
+Subsystems, Suites, and Tests
+=============================
+
+To make tests easy to find, they are grouped into suites and subsystems. A test
+suite is a group of tests which test a related area of the kernel. A subsystem
+is a set of test suites which test different parts of a kernel subsystem
+or a driver.
+
+Subsystems
+----------
+
+Every test suite must belong to a subsystem. A subsystem is a collection of one
+or more KUnit test suites which test the same driver or part of the kernel. A
+test subsystem should match a single kernel module. If the code being tested
+cannot be compiled as a module, in many cases the subsystem should correspond to
+a directory in the source tree or an entry in the ``MAINTAINERS`` file. If
+unsure, follow the conventions set by tests in similar areas.
+
+Test subsystems should be named after the code being tested, either after the
+module (wherever possible), or after the directory or files being tested. Test
+subsystems should be named to avoid ambiguity where necessary.
+
+If a test subsystem name has multiple components, they should be separated by
+underscores. *Do not* include "test" or "kunit" directly in the subsystem name
+unless we are actually testing other tests or the kunit framework itself. For
+example, subsystems could be called:
+
+``ext4``
+ Matches the module and filesystem name.
+``apparmor``
+ Matches the module name and LSM name.
+``kasan``
+ Common name for the tool, prominent part of the path ``mm/kasan``
+``snd_hda_codec_hdmi``
+ Has several components (``snd``, ``hda``, ``codec``, ``hdmi``) separated by
+ underscores. Matches the module name.
+
+Avoid names as shown in examples below:
+
+``linear-ranges``
+ Names should use underscores, not dashes, to separate words. Prefer
+ ``linear_ranges``.
+``qos-kunit-test``
+ This name should use underscores, and not have "kunit-test" as a
+ suffix. ``qos`` is also ambiguous as a subsystem name, because several parts
+ of the kernel have a ``qos`` subsystem. ``power_qos`` would be a better name.
+``pc_parallel_port``
+ The corresponding module name is ``parport_pc``, so this subsystem should also
+ be named ``parport_pc``.
+
+.. note::
+ The KUnit API and tools do not explicitly know about subsystems. They are
+ a way of categorizing test suites and naming modules which provides a
+ simple, consistent way for humans to find and run tests. This may change
+ in the future.
+
+Suites
+------
+
+KUnit tests are grouped into test suites, which cover a specific area of
+functionality being tested. Test suites can have shared initialization and
+shutdown code which is run for all tests in the suite. Not all subsystems need
+to be split into multiple test suites (for example, simple drivers).
+
+Test suites are named after the subsystem they are part of. If a subsystem
+contains several suites, the specific area under test should be appended to the
+subsystem name, separated by an underscore.
+
+In the event that there are multiple types of test using KUnit within a
+subsystem (for example, both unit tests and integration tests), they should be
+put into separate suites, with the type of test as the last element in the suite
+name. Unless these tests are actually present, avoid using ``_test``, ``_unittest``
+or similar in the suite name.
+
+The full test suite name (including the subsystem name) should be specified as
+the ``.name`` member of the ``kunit_suite`` struct, and forms the base for the
+module name. For example, test suites could include:
+
+``ext4_inode``
+ Part of the ``ext4`` subsystem, testing the ``inode`` area.
+``kunit_try_catch``
+ Part of the ``kunit`` implementation itself, testing the ``try_catch`` area.
+``apparmor_property_entry``
+ Part of the ``apparmor`` subsystem, testing the ``property_entry`` area.
+``kasan``
+ The ``kasan`` subsystem has only one suite, so the suite name is the same as
+ the subsystem name.
+
+Avoid names, for example:
+
+``ext4_ext4_inode``
+ There is no reason to state the subsystem twice.
+``property_entry``
+ The suite name is ambiguous without the subsystem name.
+``kasan_integration_test``
+ Because there is only one suite in the ``kasan`` subsystem, the suite should
+ just be called as ``kasan``. Do not redundantly add
+ ``integration_test``. It should be a separate test suite. For example, if the
+ unit tests are added, then that suite could be named as ``kasan_unittest`` or
+ similar.
+
+Test Cases
+----------
+
+Individual tests consist of a single function which tests a constrained
+codepath, property, or function. In the test output, an individual test's
+results will show up as subtests of the suite's results.
+
+Tests should be named after what they are testing. This is often the name of the
+function being tested, with a description of the input or codepath being tested.
+As tests are C functions, they should be named and written in accordance with
+the kernel coding style.
+
+.. note::
+ As tests are themselves functions, their names cannot conflict with
+ other C identifiers in the kernel. This may require some creative
+ naming. It is a good idea to make your test functions `static` to avoid
+ polluting the global namespace.
+
+Example test names include:
+
+``unpack_u32_with_null_name``
+ Tests the ``unpack_u32`` function when a NULL name is passed in.
+``test_list_splice``
+ Tests the ``list_splice`` macro. It has the prefix ``test_`` to avoid a
+ name conflict with the macro itself.
+
+
+Should it be necessary to refer to a test outside the context of its test suite,
+the *fully-qualified* name of a test should be the suite name followed by the
+test name, separated by a colon (i.e. ``suite:test``).
+
+Test Kconfig Entries
+====================
+
+Every test suite should be tied to a Kconfig entry.
+
+This Kconfig entry must:
+
+* be named ``CONFIG_<name>_KUNIT_TEST``: where <name> is the name of the test
+ suite.
+* be listed either alongside the config entries for the driver/subsystem being
+ tested, or be under [Kernel Hacking]->[Kernel Testing and Coverage]
+* depend on ``CONFIG_KUNIT``.
+* be visible only if ``CONFIG_KUNIT_ALL_TESTS`` is not enabled.
+* have a default value of ``CONFIG_KUNIT_ALL_TESTS``.
+* have a brief description of KUnit in the help text.
+* depend on the feature being tested, rather than selecting it (so that
+ enabling ``CONFIG_KUNIT_ALL_TESTS`` does not enable unrelated functionality).
+* be ``tristate``, unless there is a specific reason that the test cannot be
+ built as a module.
+
+For example, a Kconfig entry might look like:
+
+.. code-block:: none
+
+ config FOO_KUNIT_TEST
+ tristate "KUnit test for foo" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ This builds unit tests for foo.
+
+ For more information on KUnit and unit tests in general,
+ please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
+
+
+Test File and Module Names
+==========================
+
+KUnit tests are often compiled as a separate module. To avoid conflicting
+with regular modules, KUnit modules should be named after the test suite,
+followed by ``_kunit`` (e.g. if "foobar" is the core module, then
+"foobar_kunit" is the KUnit test module).
+
+Test source files, whether compiled as a separate module or an
+``#include`` in another source file, are best kept in a ``tests/``
+subdirectory to not conflict with other source files (e.g. for
+tab-completion).
+
+Note that the ``_test`` suffix has also been used in some existing
+tests. The ``_kunit`` suffix is preferred, as it makes the distinction
+between KUnit and non-KUnit tests clearer.
+
+So for the common case, name the file containing the test suite
+``tests/<suite>_kunit.c``. The ``tests`` directory should be placed at
+the same level as the code under test. For example, tests for
+``lib/string.c`` live in ``lib/tests/string_kunit.c``.
+
+If the suite name contains some or all of the name of the test's parent
+directory, it may make sense to modify the source filename to reduce
+redundancy. For example, a ``foo_firmware`` suite could be in the
+``foo/tests/firmware_kunit.c`` file.