Re: [PATCH v8 17/24] drm/probe-helper: Provide a TV get_modes helper

["Maíra Canal" <mairacanal@riseup.net>]

Hi Maxime,

On 11/10/22 08:07, Maxime Ripard wrote:
> From: Noralf Trønnes <noralf@tronnes.org>
> 
> Most of the TV connectors will need a similar get_modes implementation
> that will, depending on the drivers' capabilities, register the 480i and
> 576i modes.
> 
> That implementation will also need to set the preferred flag and order
> the modes based on the driver and users preferrence.
> 
> This is especially important to guarantee that a userspace stack such as
> Xorg can start and pick up the preferred mode while maintaining a
> working output.
> 
> Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
> Tested-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 
> ---
> Changes in v8:
> - Remove unused tv_mode_support function
> - Add unit tests
> 
> Changes in v7:
> - Used Noralf's implementation
> 
> Changes in v6:
> - New patch
> ---
>  drivers/gpu/drm/drm_probe_helper.c            |  82 ++++++++++
>  drivers/gpu/drm/tests/Makefile                |   1 +
>  drivers/gpu/drm/tests/drm_probe_helper_test.c | 209 ++++++++++++++++++++++++++
>  include/drm/drm_probe_helper.h                |   1 +
>  4 files changed, 293 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tests/drm_probe_helper_test.c b/drivers/gpu/drm/tests/drm_probe_helper_test.c
> new file mode 100644
> index 000000000000..4f295b39f746
> --- /dev/null
> +++ b/drivers/gpu/drm/tests/drm_probe_helper_test.c
> @@ -0,0 +1,209 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Kunit test for drm_probe_helper functions
> + */
> +
> +#include <drm/drm_atomic_state_helper.h>
> +#include <drm/drm_connector.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_mode.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_modeset_helper_vtables.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include <kunit/test.h>
> +
> +#include "drm_kunit_helpers.h"
> +
> +static const struct drm_display_mode ntsc_mode = {
> +	DRM_MODE("720x480i", 0, 13500,
> +		 720, 736, 800, 858, 0,
> +		 480, 486, 492, 525, 0,
> +		 DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_INTERLACE)
> +};
> +
> +static const struct drm_display_mode pal_mode = {
> +	DRM_MODE("720x576i", 0, 13500,
> +		 720, 732, 796, 864, 0,
> +		 576, 581, 587, 625, 0,
> +		 DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_INTERLACE)
> +};
> +
> +struct drm_probe_helper_test_priv {
> +	struct drm_device *drm;
> +	struct drm_connector connector;
> +};
> +
> +static const struct drm_connector_helper_funcs drm_probe_helper_connector_helper_funcs = {
> +};
> +
> +static const struct drm_connector_funcs drm_probe_helper_connector_funcs = {
> +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
> +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
> +	.reset			= drm_atomic_helper_connector_reset,
> +};
> +
> +static int drm_probe_helper_test_init(struct kunit *test)
> +{
> +	struct drm_probe_helper_test_priv *priv;
> +	struct drm_connector *connector;
> +	int ret;
> +
> +	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, priv);
> +	test->priv = priv;
> +
> +	priv->drm = drm_kunit_device_init(test, DRIVER_MODESET | DRIVER_ATOMIC,
> +					  "drm-probe-helper-test");
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->drm);
> +
> +	connector = &priv->connector;
> +	ret = drmm_connector_init(priv->drm, connector,
> +				  &drm_probe_helper_connector_funcs,
> +				  DRM_MODE_CONNECTOR_Unknown,
> +				  NULL);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	drm_connector_helper_add(connector, &drm_probe_helper_connector_helper_funcs);
> +
> +	return 0;
> +}
> +
> +struct drm_connector_helper_tv_get_modes_test {
> +	const char *name;
> +	unsigned int supported_tv_modes;
> +	enum drm_connector_tv_mode default_mode;
> +	bool cmdline;
> +	enum drm_connector_tv_mode cmdline_mode;
> +	const struct drm_display_mode **expected_modes;
> +	unsigned int num_expected_modes;
> +};
> +
> +#define _TV_MODE_TEST(_name, _supported, _default, _cmdline, _cmdline_mode, ...) 			\
> +	{												\
> +		.name = _name,										\
> +		.supported_tv_modes = _supported,							\
> +		.default_mode = _default,								\
> +		.cmdline = _cmdline,									\
> +		.cmdline_mode = _cmdline_mode,								\
> +		.expected_modes = (const struct drm_display_mode*[]) { __VA_ARGS__ }, 			\
> +		.num_expected_modes = sizeof((const struct drm_display_mode*[]) { __VA_ARGS__ }) /	\
> +				      (sizeof(const struct drm_display_mode*)),				\
> +	}
> +
> +#define TV_MODE_TEST(_name, _supported, _default, ...)			\
> +	_TV_MODE_TEST(_name, _supported, _default, false, 0, __VA_ARGS__)
> +
> +#define TV_MODE_TEST_CMDLINE(_name, _supported, _default, _cmdline, ...) \
> +	_TV_MODE_TEST(_name, _supported, _default, true, _cmdline, __VA_ARGS__)
> +
> +static void
> +drm_test_connector_helper_tv_get_modes_check(struct kunit *test)
> +{
> +	const struct drm_connector_helper_tv_get_modes_test *params = test->param_value;
> +	struct drm_probe_helper_test_priv *priv = test->priv;
> +	struct drm_connector *connector = &priv->connector;
> +	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
> +	struct drm_display_mode *mode;
> +	const struct drm_display_mode *expected;
> +	size_t len;
> +	int ret;
> +
> +	if (params->cmdline) {
> +		cmdline->tv_mode_specified = true;
> +		cmdline->tv_mode = params->cmdline_mode;
> +	}
> +
> +	ret = drm_mode_create_tv_properties(priv->drm, params->supported_tv_modes);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	drm_object_attach_property(&connector->base,
> +				   priv->drm->mode_config.tv_mode_property,
> +		 		   params->default_mode);
> +
> +	mutex_lock(&priv->drm->mode_config.mutex);
> +
> +	ret = drm_connector_helper_tv_get_modes(connector);
> +	KUNIT_EXPECT_EQ(test, ret, params->num_expected_modes);
> +
> +	list_for_each_entry(mode, &connector->probed_modes, head)
> +		len++;
> +	KUNIT_EXPECT_EQ(test, len, params->num_expected_modes);
> +
> +	if (params->num_expected_modes >= 1) {
> +		mode = list_first_entry_or_null(&connector->probed_modes,
> +						struct drm_display_mode, head);
> +		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
> +
> +		expected = params->expected_modes[0];
> +		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected);
> +
> +		KUNIT_EXPECT_TRUE(test, drm_mode_equal(mode, expected));
> +		KUNIT_EXPECT_TRUE(test, mode->type & DRM_MODE_TYPE_PREFERRED);
> +	}
> +
> +	if (params->num_expected_modes >= 2) {
> +		mode = list_next_entry(mode, head);
> +		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
> +
> +		expected = params->expected_modes[1];
> +		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected);
> +
> +		KUNIT_EXPECT_TRUE(test, drm_mode_equal(mode, expected));
> +		KUNIT_EXPECT_FALSE(test, mode->type & DRM_MODE_TYPE_PREFERRED);
> +	}
> +
> +	mutex_unlock(&priv->drm->mode_config.mutex);
> +}
> +
> +static const
> +struct drm_connector_helper_tv_get_modes_test drm_connector_helper_tv_get_modes_tests[] = {
> +	{ .name = "None" },
> +	TV_MODE_TEST("PAL", BIT(DRM_MODE_TV_MODE_PAL), DRM_MODE_TV_MODE_PAL, &pal_mode),
> +	TV_MODE_TEST("NTSC", BIT(DRM_MODE_TV_MODE_NTSC), DRM_MODE_TV_MODE_NTSC, &ntsc_mode),
> +	TV_MODE_TEST("Both, NTSC Default",
> +		     BIT(DRM_MODE_TV_MODE_NTSC) | BIT(DRM_MODE_TV_MODE_PAL),
> +		     DRM_MODE_TV_MODE_NTSC,
> +		     &ntsc_mode, &pal_mode),
> +	TV_MODE_TEST("Both, PAL Default",
> +		     BIT(DRM_MODE_TV_MODE_NTSC) | BIT(DRM_MODE_TV_MODE_PAL),
> +		     DRM_MODE_TV_MODE_PAL,
> +		     &pal_mode, &ntsc_mode),
> +	TV_MODE_TEST_CMDLINE("Both, NTSC Default, with PAL on command-line",
> +			     BIT(DRM_MODE_TV_MODE_NTSC) | BIT(DRM_MODE_TV_MODE_PAL),
> +			     DRM_MODE_TV_MODE_NTSC,
> +			     DRM_MODE_TV_MODE_PAL,
> +			     &pal_mode, &ntsc_mode),
> +	TV_MODE_TEST_CMDLINE("Both, PAL Default, with NTSC on command-line",
> +			     BIT(DRM_MODE_TV_MODE_NTSC) | BIT(DRM_MODE_TV_MODE_PAL),
> +			     DRM_MODE_TV_MODE_PAL,
> +			     DRM_MODE_TV_MODE_NTSC,
> +			     &ntsc_mode, &pal_mode),
> +};
> +
> +static void
> +drm_connector_helper_tv_get_modes_desc(const struct drm_connector_helper_tv_get_modes_test *t,
> +				       char *desc)
> +{
> +	sprintf(desc, "%s", t->name);
> +}
> +KUNIT_ARRAY_PARAM(drm_connector_helper_tv_get_modes,
> +		  drm_connector_helper_tv_get_modes_tests,
> +		  drm_connector_helper_tv_get_modes_desc);
> +
> +static struct kunit_case drm_test_connector_helper_tv_get_modes_tests[] = {
> +	KUNIT_CASE_PARAM(drm_test_connector_helper_tv_get_modes_check,
> +			 drm_connector_helper_tv_get_modes_gen_params),
> +	{ }
> +};
> +
> +static struct kunit_suite drm_test_connector_helper_tv_get_modes_suite = {
> +	.name = "drm_test_connector_helper_tv_get_modes",
> +	.init = drm_probe_helper_test_init,
> +	.test_cases = drm_test_connector_helper_tv_get_modes_tests,
> +};
> +
> +kunit_test_suites(
> +	&drm_test_connector_helper_tv_get_modes_suite
> +);

Considering that there is only one suite, you could use the
kunit_test_suite macro instead.

Moreover, it would be nice to run the checkpatch script on this test, as
there are a couple of problems with the code style.

Best Regards,
- Maíra Canal