From: Bhawanpreet Lakha <[email protected]> [Why & How] Add KUnit tests exercising every guard branch of dm_restore_drm_connector_state(): the writeback short-circuit, a missing dc_sink, a NULL connector atomic state, a NULL encoder, a crtc state without a dc stream, and an unchanged sink that skips the forced atomic commit.
Assisted-by: Copilot:Claude-Opus-4.8 Reviewed-by: Alex Hung <[email protected]> Signed-off-by: Bhawanpreet Lakha <[email protected]> Signed-off-by: Ray Wu <[email protected]> --- .../display/amdgpu_dm/amdgpu_dm_connector.c | 1 + .../tests/amdgpu_dm_connector_test.c | 177 ++++++++++++++++++ 2 files changed, 178 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c index 0e71ba498e8a..1b184699e955 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c @@ -3542,6 +3542,7 @@ void dm_restore_drm_connector_state(struct drm_device *dev, if (acrtc_state->stream->sink != aconnector->dc_sink) dm_force_atomic_commit(&aconnector->base); } +EXPORT_IF_KUNIT(dm_restore_drm_connector_state); static bool dm_edid_parser_send_cea(struct amdgpu_display_manager *dm, unsigned int offset, diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c index 76334fb840d6..9b3802dc6836 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_connector_test.c @@ -5929,6 +5929,176 @@ static void dm_test_create_i2c_hw_bus(struct kunit *test) kfree(i2c); } +/** + * dm_test_restore_state_writeback - Test writeback connectors are skipped + * @test: The KUnit test context + * + * A writeback connector short-circuits before dc_sink is ever read, so leaving + * it NULL must not crash and no connector state is created. + */ +static void dm_test_restore_state_writeback(struct kunit *test) +{ + struct drm_device *drm = dm_test_alloc_drm(test); + struct amdgpu_dm_connector *aconnector; + + aconnector = dm_test_add_connector(test, drm, + DRM_MODE_CONNECTOR_WRITEBACK); + + dm_restore_drm_connector_state(drm, &aconnector->base); + + KUNIT_EXPECT_NULL(test, aconnector->base.state); +} + +/** + * dm_test_restore_state_no_dc_sink - Test a connector without a dc_sink is a no-op + * @test: The KUnit test context + * + * With no dc_sink there is nothing to restore, so the function returns before + * touching the connector state or encoder. + */ +static void dm_test_restore_state_no_dc_sink(struct kunit *test) +{ + struct drm_device *drm = dm_test_alloc_drm(test); + struct amdgpu_dm_connector *aconnector; + + aconnector = dm_test_add_connector(test, drm, + DRM_MODE_CONNECTOR_HDMIA); + /* dc_sink left NULL by kzalloc. */ + + dm_restore_drm_connector_state(drm, &aconnector->base); + + KUNIT_EXPECT_NULL(test, aconnector->base.state); +} + +/** + * dm_test_restore_state_no_connector_state - Test a NULL connector state bails out + * @test: The KUnit test context + * + * A dc_sink is present but the connector has no atomic state, so the function + * returns before dereferencing the encoder. + */ +static void dm_test_restore_state_no_connector_state(struct kunit *test) +{ + struct drm_device *drm = dm_test_alloc_drm(test); + struct amdgpu_dm_connector *aconnector; + + aconnector = dm_test_add_connector(test, drm, + DRM_MODE_CONNECTOR_HDMIA); + aconnector->dc_sink = kunit_kzalloc(test, 1, GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, aconnector->dc_sink); + /* connector->state left NULL: the guard must catch it. */ + + dm_restore_drm_connector_state(drm, &aconnector->base); + + KUNIT_EXPECT_NULL(test, aconnector->base.encoder); +} + +/** + * dm_test_restore_state_no_encoder - Test a NULL encoder bails out + * @test: The KUnit test context + * + * A dc_sink and connector state are present but the connector is not routed to + * any encoder, so the function returns before reading the encoder's crtc. + */ +static void dm_test_restore_state_no_encoder(struct kunit *test) +{ + struct drm_device *drm = dm_test_alloc_drm(test); + struct amdgpu_dm_connector *aconnector; + + aconnector = dm_test_add_connector(test, drm, + DRM_MODE_CONNECTOR_HDMIA); + aconnector->dc_sink = kunit_kzalloc(test, 1, GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, aconnector->dc_sink); + aconnector->base.funcs->reset(&aconnector->base); + KUNIT_ASSERT_NOT_NULL(test, aconnector->base.state); + /* connector->encoder left NULL. */ + + dm_restore_drm_connector_state(drm, &aconnector->base); + + KUNIT_EXPECT_NULL(test, aconnector->base.encoder); +} + +/** + * dm_test_restore_state_no_stream - Test a crtc without a stream bails out + * @test: The KUnit test context + * + * The connector is routed to an encoder and crtc, but the crtc state carries no + * dc stream, so the function returns before comparing sinks. + */ +static void dm_test_restore_state_no_stream(struct kunit *test) +{ + struct drm_device *drm = dm_test_alloc_drm(test); + struct amdgpu_dm_connector *aconnector; + struct dm_crtc_state *acrtc_state; + struct drm_encoder *enc; + struct drm_crtc *crtc; + + aconnector = dm_test_add_connector(test, drm, + DRM_MODE_CONNECTOR_HDMIA); + aconnector->dc_sink = kunit_kzalloc(test, 1, GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, aconnector->dc_sink); + aconnector->base.funcs->reset(&aconnector->base); + + enc = kunit_kzalloc(test, sizeof(*enc), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, enc); + crtc = kunit_kzalloc(test, sizeof(*crtc), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, crtc); + acrtc_state = kunit_kzalloc(test, sizeof(*acrtc_state), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, acrtc_state); + + crtc->state = &acrtc_state->base; + enc->crtc = crtc; + aconnector->base.encoder = enc; + /* acrtc_state->stream left NULL. */ + + dm_restore_drm_connector_state(drm, &aconnector->base); + + KUNIT_EXPECT_NULL(test, acrtc_state->stream); +} + +/** + * dm_test_restore_state_same_sink - Test an unchanged sink skips the commit + * @test: The KUnit test context + * + * When the streamed sink already matches the connector's dc_sink there is + * nothing to restore, so the forced atomic commit is not issued. + */ +static void dm_test_restore_state_same_sink(struct kunit *test) +{ + struct drm_device *drm = dm_test_alloc_drm(test); + struct amdgpu_dm_connector *aconnector; + struct dm_crtc_state *acrtc_state; + struct dc_stream_state *stream; + struct drm_encoder *enc; + struct drm_crtc *crtc; + + aconnector = dm_test_add_connector(test, drm, + DRM_MODE_CONNECTOR_HDMIA); + aconnector->dc_sink = kunit_kzalloc(test, 1, GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, aconnector->dc_sink); + aconnector->base.funcs->reset(&aconnector->base); + + enc = kunit_kzalloc(test, sizeof(*enc), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, enc); + crtc = kunit_kzalloc(test, sizeof(*crtc), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, crtc); + acrtc_state = kunit_kzalloc(test, sizeof(*acrtc_state), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, acrtc_state); + stream = dm_kunit_alloc_stream(test, NULL); + KUNIT_ASSERT_NOT_NULL(test, stream); + + /* Same sink as the connector: the final branch is not taken. */ + stream->sink = aconnector->dc_sink; + acrtc_state->stream = stream; + crtc->state = &acrtc_state->base; + enc->crtc = crtc; + aconnector->base.encoder = enc; + + dm_restore_drm_connector_state(drm, &aconnector->base); + + KUNIT_EXPECT_PTR_EQ(test, stream->sink, aconnector->dc_sink); +} + /** * dm_test_get_amd_vsdb_unsupported - Test a zero VSDB version reports no support * @test: The KUnit test context @@ -8685,6 +8855,13 @@ static struct kunit_case amdgpu_dm_connector_tests[] = { /* amdgpu_dm_create_i2c */ KUNIT_CASE(dm_test_create_i2c_oem), KUNIT_CASE(dm_test_create_i2c_hw_bus), + /* dm_restore_drm_connector_state */ + KUNIT_CASE(dm_test_restore_state_writeback), + KUNIT_CASE(dm_test_restore_state_no_dc_sink), + KUNIT_CASE(dm_test_restore_state_no_connector_state), + KUNIT_CASE(dm_test_restore_state_no_encoder), + KUNIT_CASE(dm_test_restore_state_no_stream), + KUNIT_CASE(dm_test_restore_state_same_sink), /* get_amd_vsdb */ KUNIT_CASE(dm_test_get_amd_vsdb_unsupported), KUNIT_CASE(dm_test_get_amd_vsdb_supported), -- 2.43.0
