From: Alex Hung <[email protected]> [WHAT] Add KUnit tests for the AUX paths of dm_helper_dmub_aux_transfer_sync(), dm_helpers_read_mccs_caps() and dm_helpers_mccs_vcp_set(). Only their early returns and the plain I2C branch were covered before.
[HOW] dm_helper_dmub_aux_transfer_sync() is called with HPD connected so it forwards the payload to the DMUB transfer. dc->link_count is zero, so the async transfer is rejected and the engine-acquire error is reported. Both MCCS helpers pick their DDC adapter from link->aux_mode. Add a fake AUX channel that ACKs every I2C-over-AUX transaction and counts the sized writes, then route the shared MCCS fixture through it. The VCP set completes on the first write. The VCP request gets an empty reply, so every attempt is retried and the request finally fails. Assisted-by: Copilot:Claude-Opus-5 Reviewed-by: Bhawanpreet Lakha <[email protected]> Signed-off-by: Alex Hung <[email protected]> Signed-off-by: George Zhang <[email protected]> --- .../amdgpu_dm/tests/amdgpu_dm_helpers_test.c | 103 ++++++++++++++++++ 1 file changed, 103 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c index b433634e0390..b38601c1da5a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c @@ -2488,6 +2488,39 @@ static void dm_test_dmub_aux_transfer_sync_hpd_discon(struct kunit *test) KUNIT_EXPECT_EQ(test, (int)result, (int)AUX_RET_ERROR_HPD_DISCON); } +/** + * dm_test_dmub_aux_transfer_sync_hpd_connected - Test the transfer is forwarded to DMUB + * @test: The KUnit test context + * + * With HPD connected the helper forwards the payload to + * amdgpu_dm_process_dmub_aux_transfer_sync(). dc->link_count is zero, so the + * async transfer is rejected and the engine-acquire error is reported. + */ +static void dm_test_dmub_aux_transfer_sync_hpd_connected(struct kunit *test) +{ + struct aux_payload payload = {0}; + enum aux_return_code_type result = AUX_RET_SUCCESS; + struct amdgpu_device *adev; + struct dc_context *ctx; + struct dc_link *link; + int ret; + + adev = dm_kunit_alloc_adev(test); + KUNIT_ASSERT_NOT_NULL(test, adev); + ctx = dm_kunit_alloc_dc_with_ctx(test)->ctx; + link = dm_kunit_alloc_link(test); + + ctx->driver_context = adev; + mutex_init(&adev->dm.dpia_aux_lock); + init_completion(&adev->dm.dmub_aux_transfer_done); + link->hpd_status = true; + + ret = dm_helper_dmub_aux_transfer_sync(ctx, link, &payload, &result); + + KUNIT_EXPECT_EQ(test, ret, -1); + KUNIT_EXPECT_EQ(test, (int)result, (int)AUX_RET_ERROR_ENGINE_ACQUIRE); +} + /* Tests for empty stub functions (must not crash) */ /** @@ -3075,6 +3108,56 @@ static void dm_test_read_mccs_caps_i2c_failure(struct kunit *test) KUNIT_EXPECT_EQ(test, fake->reads, 0U); } +/* Counts sized I2C-over-AUX writes; the bracketing bare-address ones have size 0. */ +static unsigned int dm_test_mccs_aux_writes; + +static ssize_t dm_test_mccs_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE && msg->size) + dm_test_mccs_aux_writes++; + + msg->reply = DP_AUX_I2C_REPLY_ACK; + return msg->size; +} + +/* + * Route the fixture's link through an AUX DDC instead of the fake I2C adapter, + * so the MCCS helpers take their link->aux_mode branch. + */ +static void dm_test_mccs_use_aux(struct dm_test_mccs_fixture *fixture) +{ + struct drm_dp_aux *aux = &fixture->aconnector->dm_dp_aux.aux; + + aux->drm_dev = &fixture->adev->ddev; + aux->transfer = dm_test_mccs_aux_transfer; + drm_dp_aux_init(aux); + + fixture->aconnector->base.dev = &fixture->adev->ddev; + fixture->link->aux_mode = true; + dm_test_mccs_aux_writes = 0; +} + +/** + * dm_test_read_mccs_caps_aux_mode - Test the MCCS VCP request over I2C-over-AUX + * @test: The KUnit test context + * + * The AUX DDC ACKs both transactions but answers with an empty VCP reply, so + * every attempt is retried and the request finally fails. + */ +static void dm_test_read_mccs_caps_aux_mode(struct kunit *test) +{ + struct dm_test_mccs_fixture fixture = dm_test_alloc_mccs_fixture(test); + + dm_test_mccs_use_aux(&fixture); + fixture.link->connector_signal = SIGNAL_TYPE_HDMI_TYPE_A; + fixture.sink->edid_caps.freesync_vcp_code = 0xe3; + + dm_helpers_read_mccs_caps(fixture.ctx, fixture.link, fixture.sink); + + KUNIT_EXPECT_FALSE(test, fixture.sink->mccs_caps.freesync_supported); + KUNIT_EXPECT_EQ(test, dm_test_mccs_aux_writes, 5U); +} + /* Tests for dm_helpers_mccs_vcp_set() */ /** @@ -3188,6 +3271,23 @@ static void dm_test_mccs_vcp_set_i2c_failure(struct kunit *test) KUNIT_EXPECT_EQ(test, fake->reads, 0U); } +/** + * dm_test_mccs_vcp_set_aux_mode - Test the MCCS VCP set over I2C-over-AUX + * @test: The KUnit test context + */ +static void dm_test_mccs_vcp_set_aux_mode(struct kunit *test) +{ + struct dm_test_mccs_fixture fixture = dm_test_alloc_mccs_fixture(test); + + dm_test_mccs_use_aux(&fixture); + fixture.sink->mccs_caps.freesync_supported = true; + fixture.sink->edid_caps.freesync_vcp_code = 0xe3; + + dm_helpers_mccs_vcp_set(fixture.ctx, fixture.link, fixture.sink); + + KUNIT_EXPECT_EQ(test, dm_test_mccs_aux_writes, 1U); +} + /* Tests for dm_helpers_construct_old_payload() */ /** @@ -4809,6 +4909,7 @@ static struct kunit_case amdgpu_dm_helpers_test_cases[] = { KUNIT_CASE(dm_test_submit_i2c_partial_transfer), /* dm_helper_dmub_aux_transfer_sync */ KUNIT_CASE(dm_test_dmub_aux_transfer_sync_hpd_discon), + KUNIT_CASE(dm_test_dmub_aux_transfer_sync_hpd_connected), /* Empty stub functions */ KUNIT_CASE(dm_test_dp_update_branch_info_no_crash), KUNIT_CASE(dm_test_mst_poll_pending_down_reply_no_crash), @@ -4854,12 +4955,14 @@ static struct kunit_case amdgpu_dm_helpers_test_cases[] = { KUNIT_CASE(dm_test_read_mccs_caps_hdmi_vcp_request), KUNIT_CASE(dm_test_read_mccs_caps_legacy_pcon_vcp_request), KUNIT_CASE(dm_test_read_mccs_caps_i2c_failure), + KUNIT_CASE(dm_test_read_mccs_caps_aux_mode), /* dm_helpers_mccs_vcp_set */ KUNIT_CASE(dm_test_mccs_vcp_set_null_ctx), KUNIT_CASE(dm_test_mccs_vcp_set_not_supported), KUNIT_CASE(dm_test_mccs_vcp_set_null_link), KUNIT_CASE(dm_test_mccs_vcp_set_i2c_packet), KUNIT_CASE(dm_test_mccs_vcp_set_i2c_failure), + KUNIT_CASE(dm_test_mccs_vcp_set_aux_mode), /* dm_helpers_construct_old_payload */ KUNIT_CASE(dm_test_construct_old_payload_empty_list), KUNIT_CASE(dm_test_construct_old_payload_intervening), -- 2.55.0
