[PATCH v2] drm/amd/display: use atomic commit for panel power savings

[PATCH v2] drm/amd/display: use atomic commit for panel power savings

[Shivam Kalra via B4 Relay]

From: Shivam Kalra <shivamkalra98@zohomail.in>

panel_power_savings_store() mutates connector->state directly and sends a
hotplug event. This bypasses atomic commit handling, so the new ABM level
is only applied when userspace happens to perform another modeset, and it
races with concurrent commits.

Build an atomic state, set the level on the connector state and commit it.
If the connector is not attached to a CRTC, keep the level in the current
state so the next modeset picks it up, as before.

In amdgpu_dm_atomic_check(), drm_atomic_get_crtc_state() already adds the
CRTC to the atomic state so dm_update_crtc_state() can propagate abm_level
to the CRTC state. Stop setting new_crtc_state->connectors_changed for ABM
changes and keep it only for scaling changes, allowing ABM updates to go
through the existing non-modeset stream update path without blanking the
panel.

A previous attempt to avoid the modeset by calling into DMUB directly was
reverted because it broke the abm_gradual IGT test (8d20a066fa9b,
95aaa207e9ef). This version instead uses the normal atomic stream update
path.

Extend the backlight KUnit tests to cover the atomic commit and inactive
connector sysfs paths.

Fixes: 63d0b87213a0 ("drm/amd/display: add panel_power_savings sysfs entry to eDP connectors")
Signed-off-by: Shivam Kalra <shivamkalra98@zohomail.in>
---
Changes in v2:
- Avoid forcing a modeset for ABM-only changes, matching David Weber's
  patch [1] (Alex Hung; issue also noted by Sashiko).
- Make modeset-lock acquisition interruptible (Alex Hung).
- Inline the state update and remove the redundant connector-state
  lookup (Alex Hung).
- Reuse existing connector-state helpers in KUnit (Sashiko).
- Add a KUnit test for the sysfs commit branch with an attached CRTC.
- Run the amd_abm IGT suite, including abm_gradual.
- Link to v1: https://lore.kernel.org/r/20261031-abm-sysfs-atomic-v1-1-a99068f3b49c@zohomail.in

[1] https://lore.kernel.org/amd-gfx/20260813112634.11455-3-weber.aulendorf@gmail.com/

Testing:
- KUnit: amdgpu_dm_backlight, 74/74 tests passed.

- Hardware: v2 backported to 7.1.13-stable-manual on Rembrandt
  (DCN 3.1.2, eDP-1). All five amd_abm IGT subtests passed, including
  abm_gradual. No HOTPLUG=1 events were captured.
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c  |  3 +-
 .../amd/display/amdgpu_dm/amdgpu_dm_backlight.c    | 64 +++++++++++++++---
 .../amdgpu_dm/tests/amdgpu_dm_backlight_test.c     | 79 +++++++++++++++++++++-
 3 files changed, 132 insertions(+), 14 deletions(-)

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 dfbc384fbbdb..256699cdd0b5 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -6304,8 +6304,7 @@ STATIC_IFN_KUNIT int amdgpu_dm_atomic_check(struct drm_device *dev,
 			goto fail;
 		}
 
-		if (dm_old_con_state->abm_level != dm_new_con_state->abm_level ||
-		    dm_old_con_state->scaling != dm_new_con_state->scaling)
+		if (dm_old_con_state->scaling != dm_new_con_state->scaling)
 			new_crtc_state->connectors_changed = true;
 	}
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
index 27546febf90d..97684a58cd3d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
@@ -719,31 +719,73 @@ ssize_t panel_power_savings_store(struct device *device,
 {
 	struct drm_connector *connector = dev_get_drvdata(device);
 	struct drm_device *dev = connector->dev;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_connector_state *conn_state;
+	struct dm_connector_state *dm_conn_state;
+	struct drm_atomic_commit *state;
+	u8 abm_level;
 	long val;
 	int ret;
 
 	ret = kstrtol(buf, 0, &val);
-
 	if (ret)
 		return ret;
 
 	if (val < 0 || val > 4)
 		return -EINVAL;
 
-	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
-	if (to_dm_connector_state(connector->state)->abm_sysfs_forbidden)
+	abm_level = val ?: ABM_LEVEL_IMMEDIATE_DISABLE;
+
+	drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
+	state = drm_atomic_commit_alloc(dev);
+	if (!state) {
+		ret = -ENOMEM;
+		goto out_ctx;
+	}
+	state->acquire_ctx = &ctx;
+
+retry:
+	conn_state = drm_atomic_get_connector_state(state, connector);
+	if (IS_ERR(conn_state)) {
+		ret = PTR_ERR(conn_state);
+		goto out_backoff;
+	}
+
+	dm_conn_state = to_dm_connector_state(conn_state);
+	if (dm_conn_state->abm_sysfs_forbidden) {
 		ret = -EBUSY;
-	else
-		to_dm_connector_state(connector->state)->abm_level = val ?:
-			ABM_LEVEL_IMMEDIATE_DISABLE;
-	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+		goto out_state;
+	}
 
-	if (ret)
-		return ret;
+	dm_conn_state->abm_level = abm_level;
+
+	/*
+	 * Without a CRTC there is no stream to update and nothing to commit.
+	 * Keep the level in the current state so the next modeset picks it
+	 * up, matching the behavior of the sysfs interface.
+	 */
+	if (!conn_state->crtc) {
+		to_dm_connector_state(connector->state)->abm_level = abm_level;
+		goto out_state;
+	}
+
+	ret = drm_atomic_commit(state);
+
+out_backoff:
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
 
-	drm_kms_helper_hotplug_event(dev);
+out_state:
+	drm_atomic_commit_put(state);
+out_ctx:
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
 
-	return count;
+	return ret ? ret : count;
 }
 EXPORT_IF_KUNIT(panel_power_savings_store);
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
index c6d15fb8ad98..586e838a8f63 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
@@ -20,6 +20,7 @@
 #include "amdgpu_mode.h"
 #include "amdgpu_dm.h"
 #include "amdgpu_dm_backlight.h"
+#include "amdgpu_dm_connector.h"
 #include "amdgpu_dm_kunit_test_helpers.h"
 #include "amd_shared.h"
 #include "link_service.h"
@@ -514,6 +515,43 @@ static void dm_test_register_backlight_device_success(struct kunit *test)
 			adev->dm.backlight_dev[0]), 0);
 }
 
+static int
+dm_test_panel_power_savings_atomic_commit(struct drm_device *dev,
+					  struct drm_atomic_commit *state,
+					  bool nonblock)
+{
+	struct drm_connector_state *new_conn_state;
+	struct drm_connector *connector;
+	int i;
+
+	for_each_new_connector_in_state(state, connector, new_conn_state, i)
+		to_dm_connector_state(connector->state)->abm_level =
+			to_dm_connector_state(new_conn_state)->abm_level;
+
+	return 0;
+}
+
+static const struct drm_connector_funcs dm_test_panel_power_savings_connector_funcs = {
+	.atomic_duplicate_state = amdgpu_dm_connector_atomic_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_mode_config_funcs dm_test_panel_power_savings_mode_funcs = {
+	.atomic_commit = dm_test_panel_power_savings_atomic_commit,
+};
+
+static void
+dm_test_panel_power_savings_crtc_destroy(struct drm_crtc *crtc)
+{
+	drm_crtc_cleanup(crtc);
+}
+
+static const struct drm_crtc_funcs dm_test_panel_power_savings_crtc_funcs = {
+	.destroy = dm_test_panel_power_savings_crtc_destroy,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
 static struct drm_connector *setup_panel_power_savings_connector(struct kunit *test,
 							 struct device **device_out,
 							 struct dm_connector_state **state_out)
@@ -527,6 +565,7 @@ static struct drm_connector *setup_panel_power_savings_connector(struct kunit *t
 	adev = dm_kunit_alloc_adev(test);
 	ret = drmm_mode_config_init(&adev->ddev);
 	KUNIT_ASSERT_EQ(test, ret, 0);
+	adev->ddev.mode_config.funcs = &dm_test_panel_power_savings_mode_funcs;
 
 	connector = kunit_kzalloc(test, sizeof(*connector), GFP_KERNEL);
 	device = kunit_kzalloc(test, sizeof(*device), GFP_KERNEL);
@@ -536,7 +575,11 @@ static struct drm_connector *setup_panel_power_savings_connector(struct kunit *t
 	KUNIT_ASSERT_NOT_NULL(test, state);
 
 	connector->dev = &adev->ddev;
+	connector->funcs = &dm_test_panel_power_savings_connector_funcs;
+	connector->index = 0;
+	kref_init(&connector->base.refcount);
 	connector->state = &state->base;
+	state->base.connector = connector;
 	dev_set_drvdata(device, connector);
 	*device_out = device;
 	*state_out = state;
@@ -614,10 +657,43 @@ static void dm_test_panel_power_savings_store_sets_disable(struct kunit *test)
 	setup_panel_power_savings_connector(test, &device, &state);
 
 	KUNIT_EXPECT_EQ(test, panel_power_savings_store(device, NULL, "0", count),
-			 (ssize_t)count);
+			(ssize_t)count);
 	KUNIT_EXPECT_EQ(test, state->abm_level, ABM_LEVEL_IMMEDIATE_DISABLE);
 }
 
+/**
+ * dm_test_panel_power_savings_store_commits_with_crtc - Test store with CRTC
+ * @test: The KUnit test context
+ */
+static void dm_test_panel_power_savings_store_commits_with_crtc(struct kunit *test)
+{
+	struct dm_connector_state *state;
+	struct drm_connector *connector;
+	struct drm_crtc *crtc;
+	struct device *device;
+	size_t count = strlen("3");
+	int ret;
+
+	connector = setup_panel_power_savings_connector(test, &device, &state);
+
+	crtc = kunit_kzalloc(test, sizeof(*crtc), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, crtc);
+	ret = drm_crtc_init_with_planes(connector->dev, crtc, NULL, NULL,
+					&dm_test_panel_power_savings_crtc_funcs,
+					NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+	drm_atomic_helper_crtc_reset(crtc);
+	KUNIT_ASSERT_NOT_NULL(test, crtc->state);
+	state->base.crtc = crtc;
+
+	KUNIT_EXPECT_EQ(test, panel_power_savings_store(device, NULL, "3", count),
+			(ssize_t)count);
+	KUNIT_EXPECT_EQ(test, state->abm_level, 3);
+
+	state->base.crtc = NULL;
+	drm_crtc_cleanup(crtc);
+}
+
 /**
  * dm_test_panel_power_savings_store_forbidden - Test forbidden update
  * @test: The KUnit test context
@@ -1939,6 +2015,7 @@ static struct kunit_case dm_backlight_test_cases[] = {
 	KUNIT_CASE(dm_test_panel_power_savings_show_reports_level),
 	KUNIT_CASE(dm_test_panel_power_savings_store_sets_disable),
 	KUNIT_CASE(dm_test_panel_power_savings_store_forbidden),
+	KUNIT_CASE(dm_test_panel_power_savings_store_commits_with_crtc),
 	KUNIT_CASE(dm_test_panel_power_savings_store_rejects_invalid_text),
 	KUNIT_CASE(dm_test_panel_power_savings_store_rejects_out_of_range),
 	/* amdgpu_dm_backlight_get_device_index */

---
base-commit: ba496bb837882eb1af58f41572fc289e46c77b8c
change-id: 20261031-abm-sysfs-atomic-c79505f63a2e

Best regards,
--  
Shivam Kalra <shivamkalra98@zohomail.in>

Re: [PATCH v2] drm/amd/display: use atomic commit for panel power savings

[Mario Limonciello]

On 11/10/26 13:24, Shivam Kalra via B4 Relay wrote:
> From: Shivam Kalra <shivamkalra98@zohomail.in>
> 
> panel_power_savings_store() mutates connector->state directly and sends a
> hotplug event. This bypasses atomic commit handling, so the new ABM level
> is only applied when userspace happens to perform another modeset, and it
> races with concurrent commits.
> 
> Build an atomic state, set the level on the connector state and commit it.
> If the connector is not attached to a CRTC, keep the level in the current
> state so the next modeset picks it up, as before.
> 
> In amdgpu_dm_atomic_check(), drm_atomic_get_crtc_state() already adds the
> CRTC to the atomic state so dm_update_crtc_state() can propagate abm_level
> to the CRTC state. Stop setting new_crtc_state->connectors_changed for ABM
> changes and keep it only for scaling changes, allowing ABM updates to go
> through the existing non-modeset stream update path without blanking the
> panel.
> 
> A previous attempt to avoid the modeset by calling into DMUB directly was
> reverted because it broke the abm_gradual IGT test (8d20a066fa9b,
> 95aaa207e9ef). This version instead uses the normal atomic stream update
> path.
> 
> Extend the backlight KUnit tests to cover the atomic commit and inactive
> connector sysfs paths.
> 
> Fixes: 63d0b87213a0 ("drm/amd/display: add panel_power_savings sysfs entry to eDP connectors")
> Signed-off-by: Shivam Kalra <shivamkalra98@zohomail.in>

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>

Others should comment before merging though too.
> ---
> Changes in v2:
> - Avoid forcing a modeset for ABM-only changes, matching David Weber's
>    patch [1] (Alex Hung; issue also noted by Sashiko).
> - Make modeset-lock acquisition interruptible (Alex Hung).
> - Inline the state update and remove the redundant connector-state
>    lookup (Alex Hung).
> - Reuse existing connector-state helpers in KUnit (Sashiko).
> - Add a KUnit test for the sysfs commit branch with an attached CRTC.
> - Run the amd_abm IGT suite, including abm_gradual.
> - Link to v1: https://lore.kernel.org/r/20261031-abm-sysfs-atomic-v1-1-a99068f3b49c@zohomail.in
> 
> [1] https://lore.kernel.org/amd-gfx/20260813112634.11455-3-weber.aulendorf@gmail.com/
> 
> Testing:
> - KUnit: amdgpu_dm_backlight, 74/74 tests passed.
> 
> - Hardware: v2 backported to 7.1.13-stable-manual on Rembrandt
>    (DCN 3.1.2, eDP-1). All five amd_abm IGT subtests passed, including
>    abm_gradual. No HOTPLUG=1 events were captured.
> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c  |  3 +-
>   .../amd/display/amdgpu_dm/amdgpu_dm_backlight.c    | 64 +++++++++++++++---
>   .../amdgpu_dm/tests/amdgpu_dm_backlight_test.c     | 79 +++++++++++++++++++++-
>   3 files changed, 132 insertions(+), 14 deletions(-)
> 
> 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 dfbc384fbbdb..256699cdd0b5 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -6304,8 +6304,7 @@ STATIC_IFN_KUNIT int amdgpu_dm_atomic_check(struct drm_device *dev,
>   			goto fail;
>   		}
>   
> -		if (dm_old_con_state->abm_level != dm_new_con_state->abm_level ||
> -		    dm_old_con_state->scaling != dm_new_con_state->scaling)
> +		if (dm_old_con_state->scaling != dm_new_con_state->scaling)
>   			new_crtc_state->connectors_changed = true;
>   	}
>   
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
> index 27546febf90d..97684a58cd3d 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
> @@ -719,31 +719,73 @@ ssize_t panel_power_savings_store(struct device *device,
>   {
>   	struct drm_connector *connector = dev_get_drvdata(device);
>   	struct drm_device *dev = connector->dev;
> +	struct drm_modeset_acquire_ctx ctx;
> +	struct drm_connector_state *conn_state;
> +	struct dm_connector_state *dm_conn_state;
> +	struct drm_atomic_commit *state;
> +	u8 abm_level;
>   	long val;
>   	int ret;
>   
>   	ret = kstrtol(buf, 0, &val);
> -
>   	if (ret)
>   		return ret;
>   
>   	if (val < 0 || val > 4)
>   		return -EINVAL;
>   
> -	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> -	if (to_dm_connector_state(connector->state)->abm_sysfs_forbidden)
> +	abm_level = val ?: ABM_LEVEL_IMMEDIATE_DISABLE;
> +
> +	drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
> +	state = drm_atomic_commit_alloc(dev);
> +	if (!state) {
> +		ret = -ENOMEM;
> +		goto out_ctx;
> +	}
> +	state->acquire_ctx = &ctx;
> +
> +retry:
> +	conn_state = drm_atomic_get_connector_state(state, connector);
> +	if (IS_ERR(conn_state)) {
> +		ret = PTR_ERR(conn_state);
> +		goto out_backoff;
> +	}
> +
> +	dm_conn_state = to_dm_connector_state(conn_state);
> +	if (dm_conn_state->abm_sysfs_forbidden) {
>   		ret = -EBUSY;
> -	else
> -		to_dm_connector_state(connector->state)->abm_level = val ?:
> -			ABM_LEVEL_IMMEDIATE_DISABLE;
> -	drm_modeset_unlock(&dev->mode_config.connection_mutex);
> +		goto out_state;
> +	}
>   
> -	if (ret)
> -		return ret;
> +	dm_conn_state->abm_level = abm_level;
> +
> +	/*
> +	 * Without a CRTC there is no stream to update and nothing to commit.
> +	 * Keep the level in the current state so the next modeset picks it
> +	 * up, matching the behavior of the sysfs interface.
> +	 */
> +	if (!conn_state->crtc) {
> +		to_dm_connector_state(connector->state)->abm_level = abm_level;
> +		goto out_state;
> +	}
> +
> +	ret = drm_atomic_commit(state);
> +
> +out_backoff:
> +	if (ret == -EDEADLK) {
> +		drm_atomic_commit_clear(state);
> +		ret = drm_modeset_backoff(&ctx);
> +		if (!ret)
> +			goto retry;
> +	}
>   
> -	drm_kms_helper_hotplug_event(dev);
> +out_state:
> +	drm_atomic_commit_put(state);
> +out_ctx:
> +	drm_modeset_drop_locks(&ctx);
> +	drm_modeset_acquire_fini(&ctx);
>   
> -	return count;
> +	return ret ? ret : count;
>   }
>   EXPORT_IF_KUNIT(panel_power_savings_store);
>   
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
> index c6d15fb8ad98..586e838a8f63 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c
> @@ -20,6 +20,7 @@
>   #include "amdgpu_mode.h"
>   #include "amdgpu_dm.h"
>   #include "amdgpu_dm_backlight.h"
> +#include "amdgpu_dm_connector.h"
>   #include "amdgpu_dm_kunit_test_helpers.h"
>   #include "amd_shared.h"
>   #include "link_service.h"
> @@ -514,6 +515,43 @@ static void dm_test_register_backlight_device_success(struct kunit *test)
>   			adev->dm.backlight_dev[0]), 0);
>   }
>   
> +static int
> +dm_test_panel_power_savings_atomic_commit(struct drm_device *dev,
> +					  struct drm_atomic_commit *state,
> +					  bool nonblock)
> +{
> +	struct drm_connector_state *new_conn_state;
> +	struct drm_connector *connector;
> +	int i;
> +
> +	for_each_new_connector_in_state(state, connector, new_conn_state, i)
> +		to_dm_connector_state(connector->state)->abm_level =
> +			to_dm_connector_state(new_conn_state)->abm_level;
> +
> +	return 0;
> +}
> +
> +static const struct drm_connector_funcs dm_test_panel_power_savings_connector_funcs = {
> +	.atomic_duplicate_state = amdgpu_dm_connector_atomic_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static const struct drm_mode_config_funcs dm_test_panel_power_savings_mode_funcs = {
> +	.atomic_commit = dm_test_panel_power_savings_atomic_commit,
> +};
> +
> +static void
> +dm_test_panel_power_savings_crtc_destroy(struct drm_crtc *crtc)
> +{
> +	drm_crtc_cleanup(crtc);
> +}
> +
> +static const struct drm_crtc_funcs dm_test_panel_power_savings_crtc_funcs = {
> +	.destroy = dm_test_panel_power_savings_crtc_destroy,
> +	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
> +};
> +
>   static struct drm_connector *setup_panel_power_savings_connector(struct kunit *test,
>   							 struct device **device_out,
>   							 struct dm_connector_state **state_out)
> @@ -527,6 +565,7 @@ static struct drm_connector *setup_panel_power_savings_connector(struct kunit *t
>   	adev = dm_kunit_alloc_adev(test);
>   	ret = drmm_mode_config_init(&adev->ddev);
>   	KUNIT_ASSERT_EQ(test, ret, 0);
> +	adev->ddev.mode_config.funcs = &dm_test_panel_power_savings_mode_funcs;
>   
>   	connector = kunit_kzalloc(test, sizeof(*connector), GFP_KERNEL);
>   	device = kunit_kzalloc(test, sizeof(*device), GFP_KERNEL);
> @@ -536,7 +575,11 @@ static struct drm_connector *setup_panel_power_savings_connector(struct kunit *t
>   	KUNIT_ASSERT_NOT_NULL(test, state);
>   
>   	connector->dev = &adev->ddev;
> +	connector->funcs = &dm_test_panel_power_savings_connector_funcs;
> +	connector->index = 0;
> +	kref_init(&connector->base.refcount);
>   	connector->state = &state->base;
> +	state->base.connector = connector;
>   	dev_set_drvdata(device, connector);
>   	*device_out = device;
>   	*state_out = state;
> @@ -614,10 +657,43 @@ static void dm_test_panel_power_savings_store_sets_disable(struct kunit *test)
>   	setup_panel_power_savings_connector(test, &device, &state);
>   
>   	KUNIT_EXPECT_EQ(test, panel_power_savings_store(device, NULL, "0", count),
> -			 (ssize_t)count);
> +			(ssize_t)count);
>   	KUNIT_EXPECT_EQ(test, state->abm_level, ABM_LEVEL_IMMEDIATE_DISABLE);
>   }
>   
> +/**
> + * dm_test_panel_power_savings_store_commits_with_crtc - Test store with CRTC
> + * @test: The KUnit test context
> + */
> +static void dm_test_panel_power_savings_store_commits_with_crtc(struct kunit *test)
> +{
> +	struct dm_connector_state *state;
> +	struct drm_connector *connector;
> +	struct drm_crtc *crtc;
> +	struct device *device;
> +	size_t count = strlen("3");
> +	int ret;
> +
> +	connector = setup_panel_power_savings_connector(test, &device, &state);
> +
> +	crtc = kunit_kzalloc(test, sizeof(*crtc), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, crtc);
> +	ret = drm_crtc_init_with_planes(connector->dev, crtc, NULL, NULL,
> +					&dm_test_panel_power_savings_crtc_funcs,
> +					NULL);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +	drm_atomic_helper_crtc_reset(crtc);
> +	KUNIT_ASSERT_NOT_NULL(test, crtc->state);
> +	state->base.crtc = crtc;
> +
> +	KUNIT_EXPECT_EQ(test, panel_power_savings_store(device, NULL, "3", count),
> +			(ssize_t)count);
> +	KUNIT_EXPECT_EQ(test, state->abm_level, 3);
> +
> +	state->base.crtc = NULL;
> +	drm_crtc_cleanup(crtc);
> +}
> +
>   /**
>    * dm_test_panel_power_savings_store_forbidden - Test forbidden update
>    * @test: The KUnit test context
> @@ -1939,6 +2015,7 @@ static struct kunit_case dm_backlight_test_cases[] = {
>   	KUNIT_CASE(dm_test_panel_power_savings_show_reports_level),
>   	KUNIT_CASE(dm_test_panel_power_savings_store_sets_disable),
>   	KUNIT_CASE(dm_test_panel_power_savings_store_forbidden),
> +	KUNIT_CASE(dm_test_panel_power_savings_store_commits_with_crtc),
>   	KUNIT_CASE(dm_test_panel_power_savings_store_rejects_invalid_text),
>   	KUNIT_CASE(dm_test_panel_power_savings_store_rejects_out_of_range),
>   	/* amdgpu_dm_backlight_get_device_index */
> 
> ---
> base-commit: ba496bb837882eb1af58f41572fc289e46c77b8c
> change-id: 20261031-abm-sysfs-atomic-c79505f63a2e
> 
> Best regards,
> --
> Shivam Kalra <shivamkalra98@zohomail.in>