Re: [RFC 1/3] drm/amd/display: Introduce KUnit to DML

On Tue, Jun 7, 2022 at 6:09 PM Maíra Canal maira.canal@usp.br wrote:

KUnit unifies the test structure and provides helper tools that simplify the development. Basic use case allows running tests as regular

Thanks for sending this out! I've added some comments on the KUnit side of things.

Wording nit: was this meant to be "the development of tests." ?

processes, which makes easier to run unit tests on a development machine and to integrate the tests in a CI system.

This commit introduce a basic unit test to one part of the Display Mode

Also very minor typo: "introduces"

Library: display_mode_lib, in order to introduce the basic structure of the tests on the DML.

Signed-off-by: Maíra Canal maira.canal@usp.br

drivers/gpu/drm/amd/display/Kconfig | 1 + .../gpu/drm/amd/display/amdgpu_dm/Makefile | 5 ++ .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 + .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 3 + .../drm/amd/display/amdgpu_dm/tests/Kconfig | 29 +++++++ .../drm/amd/display/amdgpu_dm/tests/Makefile | 14 ++++ .../amdgpu_dm/tests/display_mode_lib_test.c | 83 +++++++++++++++++++ .../amd/display/amdgpu_dm/tests/dml_test.c | 23 +++++ .../amd/display/amdgpu_dm/tests/dml_test.h | 13 +++ 9 files changed, 174 insertions(+) create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig index 127667e549c1..83042e2e4d22 100644 --- a/drivers/gpu/drm/amd/display/Kconfig +++ b/drivers/gpu/drm/amd/display/Kconfig @@ -53,5 +53,6 @@ config DRM_AMD_SECURE_DISPLAY of crc of specific region via debugfs. Cooperate with specific DMCU FW.

+source "drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig"

endmenu diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile b/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile index 718e123a3230..d25b63566640 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile @@ -24,6 +24,11 @@ # It provides the control and status of dm blocks.

+AMDGPU_DM_LIBS = tests

+AMD_DM = $(addsuffix /Makefile, $(addprefix $(FULL_AMD_DISPLAY_PATH)/amdgpu_dm/,$(AMDGPU_DM_LIBS)))

+include $(AMD_DM)

AMDGPUDM = amdgpu_dm.o amdgpu_dm_irq.o amdgpu_dm_mst_types.o amdgpu_dm_color.o

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index cb1e9bb60db2..f73da1e0088f 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1655,6 +1655,7 @@ static int amdgpu_dm_init(struct amdgpu_device *adev) goto error; }

•   amdgpu_dml_test_init();
  
    DRM_DEBUG_DRIVER("KMS initialized.\n");
  
  

@@ -1678,6 +1679,8 @@ static void amdgpu_dm_fini(struct amdgpu_device *adev) { int i;

•   amdgpu_dml_test_exit();
  

•   if (adev->dm.vblank_control_workqueue) {
            destroy_workqueue(adev->dm.vblank_control_workqueue);
            adev->dm.vblank_control_workqueue = NULL;
  

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h index 3cc5c15303e6..e586d3a3d2f0 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h @@ -749,4 +749,7 @@ int dm_atomic_get_state(struct drm_atomic_state *state, struct amdgpu_dm_connector * amdgpu_dm_find_first_crtc_matching_connector(struct drm_atomic_state *state, struct drm_crtc *crtc);

+int amdgpu_dml_test_init(void); +void amdgpu_dml_test_exit(void); #endif /* __AMDGPU_DM_H__ */ diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig new file mode 100644 index 000000000000..bd1d971d4452 --- /dev/null +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig @@ -0,0 +1,29 @@ +# SPDX-License-Identifier: MIT +menu "DML Unit Tests"

•   depends on DRM_AMD_DC && KUNIT=m
  

+config DISPLAY_MODE_LIB_KUNIT_TEST

•   bool "Enable unit tests for dml/display_mode_lib" if !DML_KUNIT_TEST
  

•   default y if DML_KUNIT_TEST
  

•   help
  

•           Enables unit tests for the dml/display_mode_lib. Only useful for kernel
  

•           devs running KUnit.
  

•           For more information on KUnit and unit tests in general please refer to
  

•           the KUnit documentation in Documentation/dev-tools/kunit/.
  

•           If unsure, say N.
  

+config DML_KUNIT_TEST

•   bool "Run all unit tests for DML" if !KUNIT_ALL_TESTS
  

•   default KUNIT_ALL_TESTS
  

•   help
  

•           Enables unit tests for the Display Mode Library. Only useful for kernel
  

•           devs running KUnit.
  

•           For more information on KUnit and unit tests in general please refer to
  

•           the KUnit documentation in Documentation/dev-tools/kunit/.
  

•           If unsure, say N.
  

+endmenu diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile new file mode 100644 index 000000000000..53b38e340564 --- /dev/null +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for the KUnit Tests for DML +#

+DML_TESTS = dml_test.o

+ifdef CONFIG_DISPLAY_MODE_LIB_KUNIT_TEST +DML_TESTS += display_mode_lib_test.o +endif

+AMD_DAL_DML_TESTS = $(addprefix $(AMDDALPATH)/amdgpu_dm/tests/,$(DML_TESTS))

+AMD_DISPLAY_FILES += $(AMD_DAL_DML_TESTS) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c new file mode 100644 index 000000000000..3ea0e7fb13e3 --- /dev/null +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: MIT +/*

• • KUnit tests for dml/display_mode_lib.h
• • Copyright (C) 2022, Maíra Canal mairacanal@riseup.net
• */

+#include <kunit/test.h> +#include "../../dc/dml/display_mode_lib.h" +#include "../../dc/dml/display_mode_enums.h" +#include "dml_test.h"

+/**

• • DOC: Unit tests for AMDGPU DML display_mode_lib.h
• • The display_mode_lib.h holds the functions responsible for the instantiation
• • and logging of the Display Mode Library (DML).
• • These KUnit tests were implemented with the intention of assuring the proper
• • logging of the DML.
• */

+static void dml_get_status_message_test(struct kunit *test) +{

I think this is a case where an exhaustive test might not be warranted. The function under test is entirely just a switch statement with return statements, so the chances of things going wrong is minimal. But that's just my personal preference.

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_VALIDATION_OK), "Validation OK");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_SCALE_RATIO_TAP), "Scale ratio/tap");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_SOURCE_PIXEL_FORMAT), "Source pixel format");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_VIEWPORT_SIZE), "Viewport size");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_TOTAL_V_ACTIVE_BW), "Total vertical active bandwidth");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DIO_SUPPORT), "DIO support");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_NOT_ENOUGH_DSC), "Not enough DSC Units");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DSC_CLK_REQUIRED), "DSC clock required");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_URGENT_LATENCY), "Urgent latency");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_REORDERING_BUFFER), "Re-ordering buffer");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DISPCLK_DPPCLK), "Dispclk and Dppclk");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_TOTAL_AVAILABLE_PIPES), "Total available pipes");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_NUM_OTG), "Number of OTG");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_WRITEBACK_MODE), "Writeback mode");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_WRITEBACK_LATENCY), "Writeback latency");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_WRITEBACK_SCALE_RATIO_TAP), "Writeback scale ratio/tap");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_CURSOR_SUPPORT), "Cursor support");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_PITCH_SUPPORT), "Pitch support");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_PTE_BUFFER_SIZE), "PTE buffer size");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DSC_INPUT_BPC), "DSC input bpc");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_PREFETCH_SUPPORT), "Prefetch support");
  

•   KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_V_RATIO_PREFETCH), "Vertical ratio prefetch");
  

Hmm, perhaps we could add a test like checking that dml_get_status_message(-1) gives the expected value ("Unknown Status")? Checking values that are too small and too big is generally a nice thing to check as some of these enum->str funcs are implemented as array lookups.

+}

+static struct kunit_case display_mode_library_test_cases[] = {

•   KUNIT_CASE(dml_get_status_message_test),
  

•   {  }
  

+};

+static struct kunit_suite display_mode_lib_test_suite = {

•   .name = "dml-display-mode-lib",
  

Perhaps "display_mode_lib"?

It sounds like DML stands for that, so having both might not be necessary. Also, it seems like the agreed upon convention is to use "_" instead of "-" per https://www.kernel.org/doc/html/latest/dev-tools/kunit/style.html#suites.

•   .test_cases = display_mode_library_test_cases,
  

+};

+static struct kunit_suite *display_mode_lib_test_suites[] = { &display_mode_lib_test_suite, NULL };

+int display_mode_lib_test_init(void) +{

•   pr_info("===> Running display_mode_lib KUnit Tests");
  

•   pr_info("**********************************************************");
  

•   pr_info("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **");
  

•   pr_info("**                                                      **");
  

•   pr_info("** display_mode_lib KUnit Tests are being run. This     **");
  

•   pr_info("** means that this is a TEST kernel and should not be   **");
  

•   pr_info("** used for production.                                 **");
  

•   pr_info("**                                                      **");
  

•   pr_info("** If you see this message and you are not debugging    **");
  

•   pr_info("** the kernel, report this immediately to your vendor!  **");
  

•   pr_info("**                                                      **");
  

•   pr_info("**********************************************************");
  

David Gow proposed tainting the kernel if we ever try to run a KUnit test suite here: https://lore.kernel.org/linux-kselftest/20220513083212.3537869-2-davidgow@go...

If that goes in, then this logging might not be as necessary. I'm not sure what the status of that change is, but we're at least waiting on a v4, I think.

•   return __kunit_test_suites_init(display_mode_lib_test_suites);
  

+}

+void display_mode_lib_test_exit(void) +{

•   return __kunit_test_suites_exit(display_mode_lib_test_suites);
  

+}

Other tests have used `return` here, but it's void, so it's not really necessary.

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c new file mode 100644 index 000000000000..9a5d47597c10 --- /dev/null +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0-only

+#include "dml_test.h"

+/**

• • amdgpu_dml_test_init() - Initialise KUnit Tests for DML
• • It aggregates all KUnit Tests related to the Display Mode Library (DML).
• • The DML contains multiple modules, and to assure the modularity of the
• • tests, the KUnit Tests for a DML module are also gathered in a separated
• • module. Each KUnit Tests module is initiated in this function.
• */

+int amdgpu_dml_test_init(void) +{

•   display_mode_lib_test_init();
  

•   return 0;
  

Optional: we can make this func void. It looks like we're never looking at the return value of this func and we don't need it to make a certain signature (since we're not using it for module_init).

Daniel