root/drivers/gpu/drm/tests/drm_atomic_state_test.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Test cases for the drm_atomic_state helpers
 *
 * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
 */

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_atomic_uapi.h>
#include <drm/drm_kunit_helpers.h>
#include <drm/drm_probe_helper.h>

#define DRM_TEST_ENC_0 BIT(0)
#define DRM_TEST_ENC_1 BIT(1)
#define DRM_TEST_ENC_2 BIT(2)

#define DRM_TEST_CONN_0 BIT(0)

struct drm_clone_mode_test {
        const char *name;
        u32 encoder_mask;
        int expected_result;
};

static const struct drm_display_mode drm_atomic_test_mode = {
        DRM_MODE("1024x768", 0, 65000, 1024, 1048,
                 1184, 1344, 0, 768, 771, 777, 806, 0,
                 DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC)
};

struct drm_atomic_test_priv {
        struct drm_device drm;
        struct drm_plane *plane;
        struct drm_crtc *crtc;
        struct drm_encoder encoders[3];
        struct drm_connector connectors[2];
};

static int modeset_counter;

static void drm_test_encoder_mode_set(struct drm_encoder *encoder,
                                      struct drm_crtc_state *crtc_state,
                                      struct drm_connector_state *conn_state)
{
        modeset_counter++;
}

static const struct drm_encoder_helper_funcs drm_atomic_test_encoder_funcs = {
        .atomic_mode_set        = drm_test_encoder_mode_set,
};

static const struct drm_connector_funcs dummy_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_atomic_test_dummy_get_modes(struct drm_connector *connector)
{
        return drm_connector_helper_get_modes_fixed(connector,
                                                    &drm_atomic_test_mode);
}

static const struct drm_connector_helper_funcs dummy_connector_helper_funcs = {
        .get_modes      = drm_atomic_test_dummy_get_modes,
};

static struct drm_atomic_test_priv *
drm_atomic_test_init_drm_components(struct kunit *test, bool has_connectors)
{
        struct drm_atomic_test_priv *priv;
        struct drm_encoder *enc;
        struct drm_connector *conn;
        struct drm_device *drm;
        struct device *dev;
        int ret;

        dev = drm_kunit_helper_alloc_device(test);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);

        priv = drm_kunit_helper_alloc_drm_device(test, dev,
                                                 struct drm_atomic_test_priv,
                                                 drm,
                                                 DRIVER_MODESET | DRIVER_ATOMIC);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
        test->priv = priv;

        drm = &priv->drm;
        priv->plane = drm_kunit_helper_create_primary_plane(test, drm,
                                                            NULL,
                                                            NULL,
                                                            NULL, 0,
                                                            NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->plane);

        priv->crtc = drm_kunit_helper_create_crtc(test, drm,
                                                  priv->plane, NULL,
                                                  NULL,
                                                  NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->crtc);

        for (int i = 0; i < ARRAY_SIZE(priv->encoders); i++) {
                enc = &priv->encoders[i];

                ret = drmm_encoder_init(drm, enc, NULL,
                                        DRM_MODE_ENCODER_DSI, NULL);
                KUNIT_ASSERT_EQ(test, ret, 0);

                enc->possible_crtcs = drm_crtc_mask(priv->crtc);
        }

        priv->encoders[0].possible_clones = DRM_TEST_ENC_0 | DRM_TEST_ENC_1;
        priv->encoders[1].possible_clones = DRM_TEST_ENC_0 | DRM_TEST_ENC_1;
        priv->encoders[2].possible_clones = DRM_TEST_ENC_2;

        if (!has_connectors)
                goto done;

        BUILD_BUG_ON(ARRAY_SIZE(priv->connectors) > ARRAY_SIZE(priv->encoders));

        for (int i = 0; i < ARRAY_SIZE(priv->connectors); i++) {
                conn = &priv->connectors[i];

                ret = drmm_connector_init(drm, conn, &dummy_connector_funcs,
                                          DRM_MODE_CONNECTOR_DSI, NULL);
                KUNIT_ASSERT_EQ(test, ret, 0);

                drm_connector_helper_add(conn, &dummy_connector_helper_funcs);
                drm_encoder_helper_add(&priv->encoders[i],
                                       &drm_atomic_test_encoder_funcs);

                drm_connector_attach_encoder(conn, &priv->encoders[i]);
        }

done:
        drm_mode_config_reset(drm);

        return priv;
}

static int set_up_atomic_state(struct kunit *test,
                               struct drm_atomic_test_priv *priv,
                               struct drm_connector *connector,
                               struct drm_modeset_acquire_ctx *ctx)
{
        struct drm_device *drm = &priv->drm;
        struct drm_crtc *crtc = priv->crtc;
        struct drm_atomic_state *state;
        struct drm_connector_state *conn_state;
        struct drm_crtc_state *crtc_state;
        int ret;

        state = drm_kunit_helper_atomic_state_alloc(test, drm, ctx);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);

        if (connector) {
                conn_state = drm_atomic_get_connector_state(state, connector);
                if (IS_ERR(conn_state))
                        return PTR_ERR(conn_state);

                ret = drm_atomic_set_crtc_for_connector(conn_state, crtc);
                if (ret)
                        return ret;
        }

        crtc_state = drm_atomic_get_crtc_state(state, crtc);
        if (IS_ERR(crtc_state))
                return PTR_ERR(crtc_state);

        ret = drm_atomic_set_mode_for_crtc(crtc_state, &drm_atomic_test_mode);
        if (ret)
                return ret;

        crtc_state->enable = true;
        crtc_state->active = true;

        if (connector) {
                ret = drm_atomic_commit(state);
                if (ret)
                        return ret;
        } else {
                // dummy connector mask
                crtc_state->connector_mask = DRM_TEST_CONN_0;
        }

        return 0;
}

/*
 * Test that the DRM encoder mode_set() is called when the atomic state
 * connectors are changed but the CRTC mode is not.
 */
static void drm_test_check_connector_changed_modeset(struct kunit *test)
{
        struct drm_atomic_test_priv *priv;
        struct drm_modeset_acquire_ctx ctx;
        struct drm_connector *old_conn, *new_conn;
        struct drm_atomic_state *state;
        struct drm_device *drm;
        struct drm_connector_state *new_conn_state, *old_conn_state;
        int ret, initial_modeset_count;

        priv = drm_atomic_test_init_drm_components(test, true);
        KUNIT_ASSERT_NOT_NULL(test, priv);

        drm = &priv->drm;
        old_conn = &priv->connectors[0];
        new_conn = &priv->connectors[1];

        drm_modeset_acquire_init(&ctx, 0);

        // first modeset to enable
retry_set_up:
        ret = set_up_atomic_state(test, priv, old_conn, &ctx);
        if (ret == -EDEADLK) {
                ret = drm_modeset_backoff(&ctx);
                if (!ret)
                        goto retry_set_up;
        }
        KUNIT_ASSERT_EQ(test, ret, 0);

        state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);

        new_conn_state = drm_atomic_get_connector_state(state, new_conn);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_conn_state);

        old_conn_state = drm_atomic_get_connector_state(state, old_conn);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, old_conn_state);

        ret = drm_atomic_set_crtc_for_connector(old_conn_state, NULL);
        KUNIT_EXPECT_EQ(test, ret, 0);

        ret = drm_atomic_set_crtc_for_connector(new_conn_state, priv->crtc);
        KUNIT_EXPECT_EQ(test, ret, 0);

        initial_modeset_count = modeset_counter;

        // modeset_disables is called as part of the atomic commit tail
        ret = drm_atomic_commit(state);
        KUNIT_ASSERT_EQ(test, ret, 0);
        KUNIT_ASSERT_EQ(test, modeset_counter, initial_modeset_count + 1);

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);
}

/*
 * Test that the drm_crtc_in_clone_mode() helper can detect if a given CRTC
 * state is in clone mode
 */
static void drm_test_check_in_clone_mode(struct kunit *test)
{
        bool ret;
        const struct drm_clone_mode_test *param = test->param_value;
        struct drm_crtc_state *crtc_state;

        crtc_state = kunit_kzalloc(test, sizeof(*crtc_state), GFP_KERNEL);
        KUNIT_ASSERT_NOT_NULL(test, crtc_state);

        crtc_state->encoder_mask = param->encoder_mask;

        ret = drm_crtc_in_clone_mode(crtc_state);

        KUNIT_ASSERT_EQ(test, ret, param->expected_result);
}

/*
 * Test that the atomic commit path will succeed for valid clones (or non-cloned
 * states) and fail for states where the cloned encoders are not possible_clones
 * of each other.
 */
static void drm_test_check_valid_clones(struct kunit *test)
{
        int ret;
        const struct drm_clone_mode_test *param = test->param_value;
        struct drm_atomic_test_priv *priv;
        struct drm_modeset_acquire_ctx ctx;
        struct drm_device *drm;
        struct drm_atomic_state *state;
        struct drm_crtc_state *crtc_state;

        priv = drm_atomic_test_init_drm_components(test, false);
        KUNIT_ASSERT_NOT_NULL(test, priv);

        drm = &priv->drm;

        drm_modeset_acquire_init(&ctx, 0);

retry_set_up:
        ret = set_up_atomic_state(test, priv, NULL, &ctx);
        if (ret == -EDEADLK) {
                ret = drm_modeset_backoff(&ctx);
                if (!ret)
                        goto retry_set_up;
        }
        KUNIT_ASSERT_EQ(test, ret, 0);

        state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);

retry:
        crtc_state = drm_atomic_get_crtc_state(state, priv->crtc);
        if (PTR_ERR(crtc_state) == -EDEADLK) {
                drm_atomic_state_clear(state);
                ret = drm_modeset_backoff(&ctx);
                if (!ret)
                        goto retry;
        }
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_state);

        crtc_state->encoder_mask = param->encoder_mask;

        // force modeset
        crtc_state->mode_changed = true;

        ret = drm_atomic_helper_check_modeset(drm, state);
        if (ret == -EDEADLK) {
                drm_atomic_state_clear(state);
                ret = drm_modeset_backoff(&ctx);
                if (!ret)
                        goto retry;
        }
        KUNIT_ASSERT_EQ(test, ret, param->expected_result);

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);
}

static void drm_check_in_clone_mode_desc(const struct drm_clone_mode_test *t,
                                      char *desc)
{
        sprintf(desc, "%s", t->name);
}

static void drm_check_valid_clones_desc(const struct drm_clone_mode_test *t,
                                      char *desc)
{
        sprintf(desc, "%s", t->name);
}

static const struct drm_clone_mode_test drm_clone_mode_tests[] = {
        {
                .name = "in_clone_mode",
                .encoder_mask = DRM_TEST_ENC_0 | DRM_TEST_ENC_1,
                .expected_result = true,
        },
        {
                .name = "not_in_clone_mode",
                .encoder_mask = DRM_TEST_ENC_0,
                .expected_result = false,
        },
};

static const struct drm_clone_mode_test drm_valid_clone_mode_tests[] = {
        {
                .name = "not_in_clone_mode",
                .encoder_mask = DRM_TEST_ENC_0,
                .expected_result = 0,
        },

        {
                .name = "valid_clone",
                .encoder_mask = DRM_TEST_ENC_0 | DRM_TEST_ENC_1,
                .expected_result = 0,
        },
        {
                .name = "invalid_clone",
                .encoder_mask = DRM_TEST_ENC_0 | DRM_TEST_ENC_2,
                .expected_result = -EINVAL,
        },
};

KUNIT_ARRAY_PARAM(drm_check_in_clone_mode, drm_clone_mode_tests,
                  drm_check_in_clone_mode_desc);

KUNIT_ARRAY_PARAM(drm_check_valid_clones, drm_valid_clone_mode_tests,
                  drm_check_valid_clones_desc);

static struct kunit_case drm_test_check_modeset_test[] = {
        KUNIT_CASE(drm_test_check_connector_changed_modeset),
        {}
};

static struct kunit_case drm_in_clone_mode_check_test[] = {
        KUNIT_CASE_PARAM(drm_test_check_in_clone_mode,
                         drm_check_in_clone_mode_gen_params),
        KUNIT_CASE_PARAM(drm_test_check_valid_clones,
                         drm_check_valid_clones_gen_params),
        {}
};

static struct kunit_suite drm_test_check_modeset_test_suite = {
        .name = "drm_validate_modeset",
        .test_cases = drm_test_check_modeset_test,
};

static struct kunit_suite drm_in_clone_mode_check_test_suite = {
        .name = "drm_validate_clone_mode",
        .test_cases = drm_in_clone_mode_check_test,
};

kunit_test_suites(&drm_in_clone_mode_check_test_suite,
                  &drm_test_check_modeset_test_suite);

MODULE_AUTHOR("Jessica Zhang <quic_jesszhan@quicinc.com");
MODULE_DESCRIPTION("Test cases for the drm_atomic_helper functions");
MODULE_LICENSE("GPL");