Re: [PATCH v2 00/17] drm: Introduce Kunit Tests to VC4

["Maíra Canal" <mcanal@igalia.com>]

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>
> 
> ---
> 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.tech
> 
> ---
> 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(-)
> ---
> base-commit: 199557fab92548f8e9d5207e385097213abe0cab
> change-id: 20221123-rpi-kunit-tests-87a388492a73
> 
> Best regards,