On 11/28/22 11:53, Maxime Ripard wrote:

Hi,

This series introduce Kunit tests to the vc4 KMS driver, but unlike what we have been doing so far in KMS, it actually tests the atomic modesetting code.

In order to do so, I've had to improve a fair bit on the Kunit helpers already found in the tree in order to register a full blown and somewhat functional KMS driver.

It's of course relying on a mock so that we can test it anywhere. The mocking approach created a number of issues, the main one being that we need to create a decent mock in the first place, see patch 22. The basic idea is that I created some structures to provide a decent approximation of the actual hardware, and that would support both major architectures supported by vc4.

This is of course meant to evolve over time and support more tests, but I've focused on testing the HVS FIFO assignment code which is fairly tricky (and the tests have actually revealed one more bug with our current implementation). I used to have a userspace implementation of those tests, where I would copy and paste the kernel code and run the tests on a regular basis. It's was obviously fairly suboptimal, so it seemed like the perfect testbed for that series.

It can be run using: ./tools/testing/kunit/kunit.py run \ --kunitconfig=drivers/gpu/drm/vc4/tests/.kunitconfig \ --cross_compile aarch64-linux-gnu- --arch arm64

Let me know what you think, Maxime

Hi Maxime,

It is great to see some device mocking with KUnit! Other than the comments that I pointed out in the series, I believe that a small entry on the VC4 documentation would be nice to cover how to run the tests and also what the tests are currently covering.

Best Regards, - Maíra Canal

To: David Airlie airlied@gmail.com To: Daniel Vetter daniel@ffwll.ch To: Maarten Lankhorst maarten.lankhorst@linux.intel.com To: Maxime Ripard mripard@kernel.org To: Thomas Zimmermann tzimmermann@suse.de Cc: Dave Stevenson dave.stevenson@raspberrypi.com Cc: Javier Martinez Canillas javierm@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Maíra Canal mairacanal@riseup.net Cc: Brendan Higgins brendan.higgins@linux.dev Cc: David Gow davidgow@google.com Cc: linux-kselftest@vger.kernel.org Cc: kunit-dev@googlegroups.com Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Maxime Ripard maxime@cerno.tech

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Changes in v2:

• Added some documentation for public functions
• Removed the fake device probe/remove workqueue
• Made sure the tests could be compiled as modules
• Moved the vc4 tests in the vc4 module
• Applied some of the preliminary patches
• Rebased on top of current drm-misc-next branch
• Fixed checkpatch issues
• Introduced BCM2835 (Pi0-3) tests for muxing
• Introduced tests to cover past bugs we had
• Link to v1: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v1-0-051a0bb60a16@cerno.t...

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Maxime Ripard (17): drm/tests: helpers: Move the helper header to include/drm drm/tests: helpers: Document drm_kunit_device_init() drm/tests: helpers: Rename the device init helper drm/tests: helpers: Remove the name parameter drm/tests: helpers: Create the device in another function drm/tests: helpers: Switch to a platform_device drm/tests: helpers: Make sure the device is bound drm/tests: helpers: Allow for a custom device struct to be allocated drm/tests: helpers: Allow to pass a custom drm_driver drm/tests: Add a test for DRM managed actions drm/vc4: Move HVS state to main header drm/vc4: crtc: Introduce a lower-level crtc init helper drm/vc4: crtc: Make encoder lookup helper public drm/vc4: hvs: Provide a function to initialize the HVS structure drm/vc4: tests: Introduce a mocking infrastructure drm/vc4: tests: Fail the current test if we access a register drm/vc4: tests: Add unit test suite for the PV muxing

drivers/gpu/drm/tests/Makefile | 1 + drivers/gpu/drm/tests/drm_client_modeset_test.c | 19 +- drivers/gpu/drm/tests/drm_kunit_helpers.c | 106 ++- drivers/gpu/drm/tests/drm_kunit_helpers.h | 11 - drivers/gpu/drm/tests/drm_managed_test.c | 71 ++ drivers/gpu/drm/tests/drm_modes_test.c | 19 +- drivers/gpu/drm/tests/drm_probe_helper_test.c | 20 +- drivers/gpu/drm/vc4/Kconfig | 15 + drivers/gpu/drm/vc4/Makefile | 7 + drivers/gpu/drm/vc4/tests/.kunitconfig | 14 + drivers/gpu/drm/vc4/tests/vc4_mock.c | 200 +++++ drivers/gpu/drm/vc4/tests/vc4_mock.h | 63 ++ drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c | 41 + drivers/gpu/drm/vc4/tests/vc4_mock_output.c | 138 +++ drivers/gpu/drm/vc4/tests/vc4_mock_plane.c | 47 + drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c | 1039 +++++++++++++++++++++++ drivers/gpu/drm/vc4/vc4_crtc.c | 102 ++- drivers/gpu/drm/vc4/vc4_dpi.c | 13 +- drivers/gpu/drm/vc4/vc4_drv.c | 4 +- drivers/gpu/drm/vc4/vc4_drv.h | 91 +- drivers/gpu/drm/vc4/vc4_dsi.c | 9 +- drivers/gpu/drm/vc4/vc4_hdmi_regs.h | 4 + drivers/gpu/drm/vc4/vc4_hvs.c | 81 +- drivers/gpu/drm/vc4/vc4_kms.c | 25 +- drivers/gpu/drm/vc4/vc4_txp.c | 15 +- drivers/gpu/drm/vc4/vc4_vec.c | 13 +- include/drm/drm_kunit_helpers.h | 91 ++ 27 files changed, 2087 insertions(+), 172 deletions(-)

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base-commit: 199557fab92548f8e9d5207e385097213abe0cab change-id: 20221123-rpi-kunit-tests-87a388492a73

Best regards,