diff mbox series

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

Message ID 20220608010709.272962-2-maira.canal@usp.br (mailing list archive)
State New, archived
Headers show
Series drm/amd/display: Introduce KUnit to Display Mode Library | expand

Commit Message

Maíra Canal June 8, 2022, 1:07 a.m. UTC
KUnit unifies the test structure and provides helper tools that simplify
the development. Basic use case allows running tests as regular
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
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

Comments

Daniel Latypov June 8, 2022, 2:36 a.m. UTC | #1
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@google.com/

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
Maíra Canal June 15, 2022, 3:05 p.m. UTC | #2
Hi Daniel

Thank you for your feedback! We are working on the comments you pointed out.

On 6/7/22 23:36, Daniel Latypov wrote:
> On Tue, Jun 7, 2022 at 6:09 PM Maíra Canal <maira.canal@usp.br> wrote:
>> 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.

Maybe we left out some explanation on this unit test. This RFC was more of an introduction to our project. We wanted to show you the test structure we plan to develop the unit tests during this summer. Initially, we were thinking of using the typical kunit_test_suites structure, but we end up checking out that it wasn't possible, due to the need to insert the tests inside the AMDGPU stack.

We also agree with you that this test is trivial and it will probably be removed from the final version. We plan to have more functional tests that explore the inner workings of the DML and especially the corner cases as you said.

We apologize if we didn't make it clear in the Cover Letter that this RFC is more of an introduction to the project we pretend to develop in the summer.

If you have suggestions on how we can improve the use of KUnit, it is welcome.

>>
>> +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@google.com/
> 
> 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.

This is going to be great! We will keep an eye on this proposal.

- Maíra Canal
diff mbox series

Patch

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)
+{
+	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");
+}
+
+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",
+	.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("**********************************************************");
+
+	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);
+}
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;
+}
+
+void amdgpu_dml_test_exit(void)
+{
+	display_mode_lib_test_exit();
+}
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h
new file mode 100644
index 000000000000..2786db9d0e87
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h
@@ -0,0 +1,13 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef DML_TEST_H_
+#define DML_TEST_H_
+
+#if defined (CONFIG_DISPLAY_MODE_LIB_KUNIT_TEST)
+int display_mode_lib_test_init(void);
+void display_mode_lib_test_exit(void);
+#else
+static inline int display_mode_lib_test_init(void) { return 0; }
+static inline void display_mode_lib_test_exit(void) { }
+#endif
+
+#endif