[PATCH v6 00/15] drm: Add DRM_MODE_ATOMIC_RESET flag

[PATCH v6 00/15] drm: Add DRM_MODE_ATOMIC_RESET flag

[Maxime Ripard]

Hi,

Userspace currently has no atomic way to bring a display pipeline back
to a pristine state. A compositor that wants to start from a known
baseline must explicitly set every property on every KMS object to its
default value, which requires tracking which properties exist and what
their defaults are. This is fragile and must be updated every time a
new property is added to the kernel.

This series introduces a new DRM_MODE_ATOMIC_RESET flag for the
atomic ioctl. When set, the kernel fills the commit with default
states for all KMS objects before applying the properties supplied in
the request. Properties not explicitly included remain at their
defaults. This allows userspace to describe the desired end state
declaratively, without caring about the current state or the full set
of properties.

The bulk of the series extracts the state insertion logic from each
drm_atomic_get_*_state() into standalone helpers, since the
fill_with_defaults path creates states through atomic_create_state()
rather than atomic_duplicate_state() and cannot reuse the existing
functions directly.

A driver-specific property is added to vkms planes for testing.
Standard properties are impractical for this: compositors like Mutter
enumerate all known properties, making it hard to isolate the reset
behavior in a test.

Mutter has a working implementation using the new flag, with a
vkms-based test exercising the reset behavior:
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/5309

And we have IGT tests as well:
https://lore.kernel.org/igt-dev/20260916095159.2896630-1-mripard@kernel.org/

This series relies on all drivers implementing atomic_create_state.
The conversion is in progress but not yet complete.

Let me know what you think,
Maxime

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
Changes in v6:
- If using a lease, only considered the leased objects
- Fix amdgpu plane atomic_create_state implementation
- Link to v5: https://lore.kernel.org/r/20261016-drm-reset-state-flag-v5-0-dad2d64b693b@kernel.org

Changes in v5:
- Fix bisection issue
- Improve the documentation
- Fix connector hotplugging issue
- Added kunit tests for drm_atomic_commit_fill_with_defaults()
- Link to v4: https://lore.kernel.org/r/20260918-drm-reset-state-flag-v4-0-5ad106370f05@kernel.org

Changes in v4:
- Improve the drm_atomic_get_private_obj_state and
  drm_atomic_get_connector_state array reallocations
- Return void on functions to insert an object state into a commit when
  it cannot fail
- Rename drm_atomic_can_create_state() into
  drm_atomic_implements_create_state()
- Move capability check from drm_atomic_commit_fill_with_defaults to its
  caller 
- Added IGT test
- Link to v3: https://lore.kernel.org/r/20260908-drm-reset-state-flag-v3-0-905570f387a4@kernel.org

Changes in v3:
- Rebased on top of the latest atomic_create_state series
- Sebastian Wick created and tested this work with mutter and vkms
- Fix colorop locking
- Link to v2: https://lore.kernel.org/r/20260812-drm-reset-state-flag-v2-0-e96ce13317dd@kernel.org

Changes in v2:
- Fix bisection
- Add capability to let userspace know if it can reset the state
- Link to v1: https://lore.kernel.org/r/20260708-drm-reset-state-flag-v1-0-c37dc985485d@kernel.org

---
Maxime Ripard (14):
      drm/amd/display: Fix planes atomic_create_state implementation
      drm/atomic: Switch to krealloc_array() in drm_atomic_get_private_obj_state()
      drm/atomic: Use __GFP_ZERO instead of explicit memset in drm_atomic_get_private_obj_state()
      drm/atomic: Use __GFP_ZERO instead of explicit memset in drm_atomic_get_connector_state()
      drm/atomic: Create function to insert CRTC state into a commit
      drm/atomic: Create function to insert plane state into a commit
      drm/atomic: Create function to insert colorop state into a commit
      drm/atomic: Create function to insert private obj state into a commit
      drm/atomic: Create function to insert connector state into a commit
      drm/atomic: Add drm_atomic_implements_create_state() helper
      drm/atomic: Allow filling a commit with pristine object states
      drm/tests: atomic: Add tests for drm_atomic_commit_fill_with_defaults()
      drm/vkms: Switch container_of helpers to container_of_const
      drm/vkms: Add driver-specific plane property for testing

Sebastian Wick (1):
      drm/atomic-uapi: Add DRM_MODE_ATOMIC_RESET flag

 .../drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c    |   3 -
 drivers/gpu/drm/drm_atomic.c                       | 381 +++++++++++++++++----
 drivers/gpu/drm/drm_atomic_uapi.c                  |  18 +
 drivers/gpu/drm/drm_ioctl.c                        |   4 +
 drivers/gpu/drm/tests/drm_atomic_test.c            | 141 +++++++-
 drivers/gpu/drm/vkms/vkms_drv.h                    |  11 +-
 drivers/gpu/drm/vkms/vkms_plane.c                  |  61 +++-
 include/drm/drm_atomic.h                           |   4 +
 include/uapi/drm/drm.h                             |  10 +
 include/uapi/drm/drm_mode.h                        |  14 +-
 10 files changed, 572 insertions(+), 75 deletions(-)
---
base-commit: 489a8539ca6f347102c1334c2f08198abacc86c8
change-id: 20260708-drm-reset-state-flag-2fb2b5711f97

Best regards,
-- 
Maxime Ripard <mripard@kernel.org>

[PATCH v6 01/15] drm/amd/display: Fix planes atomic_create_state implementation

[Maxime Ripard]

Commit 2bcec01cf105 ("drm/amdgpu_dm: Convert to atomic_create_state")
converted the amdgpu planes to use atomic_create_state instead of reset.

Unlike reset, atomic_create_state is meant to allocate a new default
state without any side effect on the hardware or software state.

However, during the conversion we forgot to remove the call to destroy
the existing plane state if any. While this was expected from a reset
implementation, it's not for an atomic_create_state one. Remove it.

Fixes: 2bcec01cf105 ("drm/amdgpu_dm: Convert to atomic_create_state")
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
index 2f88b9d65b82..779dabb7fc51 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
@@ -1821,7 +1821,4 @@ STATIC_IFN_KUNIT struct drm_plane_state *amdgpu_dm_plane_drm_plane_create_state(
 	}
 
-	if (plane->state)
-		plane->funcs->atomic_destroy_state(plane, plane->state);
-
 	__drm_atomic_helper_plane_state_init(&amdgpu_state->base, plane);
 	amdgpu_state->degamma_tf = AMDGPU_TRANSFER_FUNCTION_DEFAULT;

-- 
2.55.0

[PATCH v6 02/15] drm/atomic: Switch to krealloc_array() in drm_atomic_get_private_obj_state()

[Maxime Ripard]

The drm_atomic_get_private_obj_state() function manually computes the
allocation size by multiplying the element count by the element size
before passing it to krealloc().

krealloc_array() handles this multiplication internally and includes
overflow checking. Switch to it and drop the now-unused size variable.

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 9bb761eda59f..aa47c647df31 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1080,5 +1080,4 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 {
 	int index, num_objs, ret;
-	size_t size;
 	struct __drm_private_objs_state *arr;
 	struct drm_private_state *obj_state;
@@ -1096,6 +1095,6 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 
 	num_objs = state->num_private_objs + 1;
-	size = sizeof(*state->private_objs) * num_objs;
-	arr = krealloc(state->private_objs, size, GFP_KERNEL);
+	arr = krealloc_array(state->private_objs, num_objs,
+			     sizeof(*state->private_objs), GFP_KERNEL);
 	if (!arr)
 		return ERR_PTR(-ENOMEM);

-- 
2.55.0

[PATCH v6 03/15] drm/atomic: Use __GFP_ZERO instead of explicit memset in drm_atomic_get_private_obj_state()

[Maxime Ripard]

The drm_atomic_get_private_obj_state() function allocates a new entry in
the private_objs array using krealloc_array(), then zeroes the new entry
with a separate memset() call.

However, since krealloc_array() already supports the __GFP_ZERO flag to
zero newly allocated memory, the explicit memset() is redundant.

Pass __GFP_ZERO to krealloc_array() and drop the manual memset().

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index aa47c647df31..43b58e9b25e4 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1096,5 +1096,5 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 	num_objs = state->num_private_objs + 1;
 	arr = krealloc_array(state->private_objs, num_objs,
-			     sizeof(*state->private_objs), GFP_KERNEL);
+			     sizeof(*state->private_objs), GFP_KERNEL | __GFP_ZERO);
 	if (!arr)
 		return ERR_PTR(-ENOMEM);
@@ -1102,5 +1102,4 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 	state->private_objs = arr;
 	index = state->num_private_objs;
-	memset(&state->private_objs[index], 0, sizeof(*state->private_objs));
 
 	obj_state = obj->funcs->atomic_duplicate_state(obj);

-- 
2.55.0

[PATCH v6 04/15] drm/atomic: Use __GFP_ZERO instead of explicit memset in drm_atomic_get_connector_state()

[Maxime Ripard]

The drm_atomic_get_connector_state() function grows the connectors array
with krealloc_array() when the requested connector index exceeds the
current allocation, then zeroes the new entries with a separate memset()
call.

Since krealloc_array() supports the __GFP_ZERO flag to zero newly
allocated memory, the explicit memset() is unnecessary.

Pass __GFP_ZERO to krealloc_array() and drop the manual memset().

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 43b58e9b25e4..80436adcfb7f 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1391,12 +1391,9 @@ drm_atomic_get_connector_state(struct drm_atomic_commit *state,
 
 		c = krealloc_array(state->connectors, alloc,
-				   sizeof(*state->connectors), GFP_KERNEL);
+				   sizeof(*state->connectors), GFP_KERNEL | __GFP_ZERO);
 		if (!c)
 			return ERR_PTR(-ENOMEM);
 
 		state->connectors = c;
-		memset(&state->connectors[state->num_connector], 0,
-		       sizeof(*state->connectors) * (alloc - state->num_connector));
-
 		state->num_connector = alloc;
 	}

-- 
2.55.0

[PATCH v6 05/15] drm/atomic: Create function to insert CRTC state into a commit

[Maxime Ripard]

drm_atomic_get_crtc_state() allocates a new CRTC state by duplicating
the current one and inserts it into the atomic commit as a single
operation.

However, a later change will need to insert a CRTC state into a
commit without going through the full allocation and duplication path
in drm_atomic_get_crtc_state().

Extract the state insertion logic into a new static
drm_atomic_commit_set_crtc_state() helper, and convert
drm_atomic_get_crtc_state() to use it.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 80436adcfb7f..178eca95d0e3 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -434,4 +434,19 @@ void __drm_atomic_commit_free(struct kref *ref)
 EXPORT_SYMBOL(__drm_atomic_commit_free);
 
+static void drm_atomic_commit_set_crtc_state(struct drm_atomic_commit *commit,
+					     struct drm_crtc *crtc,
+					     struct drm_crtc_state *crtc_state)
+{
+	int index = drm_crtc_index(crtc);
+
+	drm_modeset_lock_assert_held(&crtc->mutex);
+
+	commit->crtcs[index].state_to_destroy = crtc_state;
+	commit->crtcs[index].old_state = crtc->state;
+	commit->crtcs[index].new_state = crtc_state;
+	commit->crtcs[index].ptr = crtc;
+	crtc_state->state = commit;
+}
+
 /**
  * drm_atomic_get_crtc_state - get CRTC state
@@ -456,5 +471,5 @@ drm_atomic_get_crtc_state(struct drm_atomic_commit *state,
 			  struct drm_crtc *crtc)
 {
-	int ret, index = drm_crtc_index(crtc);
+	int ret;
 	struct drm_crtc_state *crtc_state;
 
@@ -474,9 +489,5 @@ drm_atomic_get_crtc_state(struct drm_atomic_commit *state,
 		return ERR_PTR(-ENOMEM);
 
-	state->crtcs[index].state_to_destroy = crtc_state;
-	state->crtcs[index].old_state = crtc->state;
-	state->crtcs[index].new_state = crtc_state;
-	state->crtcs[index].ptr = crtc;
-	crtc_state->state = state;
+	drm_atomic_commit_set_crtc_state(state, crtc, crtc_state);
 
 	drm_dbg_atomic(state->dev, "Added [CRTC:%d:%s] %p state to %p\n",

-- 
2.55.0

[PATCH v6 06/15] drm/atomic: Create function to insert plane state into a commit

[Maxime Ripard]

drm_atomic_get_plane_state() allocates a new plane state by
duplicating the current one and inserts it into the atomic commit as
a single operation.

However, a later change will need to insert a plane state into a
commit without going through the full allocation and duplication path
in drm_atomic_get_plane_state().

Extract the state insertion logic into a new static
drm_atomic_commit_set_plane_state() helper, and convert
drm_atomic_get_plane_state() to use it.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 178eca95d0e3..b26458ee98d8 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -631,4 +631,19 @@ static int drm_atomic_connector_check(struct drm_connector *connector,
 }
 
+static void drm_atomic_commit_set_plane_state(struct drm_atomic_commit *commit,
+					      struct drm_plane *plane,
+					      struct drm_plane_state *plane_state)
+{
+	int index = drm_plane_index(plane);
+
+	drm_modeset_lock_assert_held(&plane->mutex);
+
+	commit->planes[index].state_to_destroy = plane_state;
+	commit->planes[index].old_state = plane->state;
+	commit->planes[index].new_state = plane_state;
+	commit->planes[index].ptr = plane;
+	plane_state->state = commit;
+}
+
 /**
  * drm_atomic_get_plane_state - get plane state
@@ -649,5 +664,5 @@ drm_atomic_get_plane_state(struct drm_atomic_commit *state,
 			  struct drm_plane *plane)
 {
-	int ret, index = drm_plane_index(plane);
+	int ret;
 	struct drm_plane_state *plane_state;
 
@@ -672,9 +687,5 @@ drm_atomic_get_plane_state(struct drm_atomic_commit *state,
 		return ERR_PTR(-ENOMEM);
 
-	state->planes[index].state_to_destroy = plane_state;
-	state->planes[index].ptr = plane;
-	state->planes[index].old_state = plane->state;
-	state->planes[index].new_state = plane_state;
-	plane_state->state = state;
+	drm_atomic_commit_set_plane_state(state, plane, plane_state);
 
 	drm_dbg_atomic(plane->dev, "Added [PLANE:%d:%s] %p state to %p\n",

-- 
2.55.0

[PATCH v6 07/15] drm/atomic: Create function to insert colorop state into a commit

[Maxime Ripard]

drm_atomic_get_colorop_state() allocates a new colorop state by
duplicating the current one and inserts it into the atomic commit as
a single operation.

However, a later change will need to insert a colorop state into a
commit without going through the full allocation and duplication path
in drm_atomic_get_colorop_state().

Extract the state insertion logic into a new static
drm_atomic_commit_set_colorop_state() helper, and convert
drm_atomic_get_colorop_state() to use it.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index b26458ee98d8..807b575ecc54 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -705,4 +705,19 @@ drm_atomic_get_plane_state(struct drm_atomic_commit *state,
 EXPORT_SYMBOL(drm_atomic_get_plane_state);
 
+static void drm_atomic_commit_set_colorop_state(struct drm_atomic_commit *commit,
+						struct drm_colorop *colorop,
+						struct drm_colorop_state *colorop_state)
+{
+	int index = drm_colorop_index(colorop);
+
+	drm_modeset_lock_assert_held(&colorop->plane->mutex);
+
+	commit->colorops[index].state_to_destroy = colorop_state;
+	commit->colorops[index].old_state = colorop->state;
+	commit->colorops[index].new_state = colorop_state;
+	commit->colorops[index].ptr = colorop;
+	colorop_state->state = commit;
+}
+
 /**
  * drm_atomic_get_colorop_state - get colorop state
@@ -724,5 +739,5 @@ drm_atomic_get_colorop_state(struct drm_atomic_commit *state,
 			     struct drm_colorop *colorop)
 {
-	int ret, index = drm_colorop_index(colorop);
+	int ret;
 	struct drm_colorop_state *colorop_state;
 
@@ -741,9 +756,5 @@ drm_atomic_get_colorop_state(struct drm_atomic_commit *state,
 		return ERR_PTR(-ENOMEM);
 
-	state->colorops[index].state_to_destroy = colorop_state;
-	state->colorops[index].ptr = colorop;
-	state->colorops[index].old_state = colorop->state;
-	state->colorops[index].new_state = colorop_state;
-	colorop_state->state = state;
+	drm_atomic_commit_set_colorop_state(state, colorop, colorop_state);
 
 	drm_dbg_atomic(colorop->dev, "Added [COLOROP:%d:%d] %p state to %p\n",

-- 
2.55.0

[PATCH v6 08/15] drm/atomic: Create function to insert private obj state into a commit

[Maxime Ripard]

drm_atomic_get_private_obj_state() allocates a new private object
state by duplicating the current one and inserts it into the atomic
commit as a single operation.

However, a later change will need to insert a private object state
into a commit without going through the full allocation and
duplication path in drm_atomic_get_private_obj_state().

Extract the state insertion logic, including the array reallocation,
into a new static drm_atomic_commit_set_private_obj_state() helper,
and convert drm_atomic_get_private_obj_state() to use it.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 53 +++++++++++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 807b575ecc54..513e91ad2fdc 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1096,4 +1096,33 @@ drm_atomic_private_obj_fini(struct drm_private_obj *obj)
 EXPORT_SYMBOL(drm_atomic_private_obj_fini);
 
+static int drm_atomic_commit_set_private_obj_state(struct drm_atomic_commit *commit,
+						   struct drm_private_obj *obj,
+						   struct drm_private_state *obj_state)
+{
+	struct __drm_private_objs_state *arr;
+	int index, num_objs;
+
+	drm_modeset_lock_assert_held(&obj->lock);
+
+	num_objs = commit->num_private_objs + 1;
+	arr = krealloc_array(commit->private_objs, num_objs,
+			     sizeof(*commit->private_objs), GFP_KERNEL | __GFP_ZERO);
+	if (!arr)
+		return -ENOMEM;
+
+	commit->private_objs = arr;
+	index = commit->num_private_objs;
+
+	commit->private_objs[index].state_to_destroy = obj_state;
+	commit->private_objs[index].old_state = obj->state;
+	commit->private_objs[index].new_state = obj_state;
+	commit->private_objs[index].ptr = obj;
+	obj_state->state = commit;
+
+	commit->num_private_objs = num_objs;
+
+	return 0;
+}
+
 /**
  * drm_atomic_get_private_obj_state - get private object state
@@ -1112,6 +1141,5 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 				 struct drm_private_obj *obj)
 {
-	int index, num_objs, ret;
-	struct __drm_private_objs_state *arr;
+	int ret;
 	struct drm_private_state *obj_state;
 
@@ -1127,24 +1155,13 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 		return ERR_PTR(ret);
 
-	num_objs = state->num_private_objs + 1;
-	arr = krealloc_array(state->private_objs, num_objs,
-			     sizeof(*state->private_objs), GFP_KERNEL | __GFP_ZERO);
-	if (!arr)
-		return ERR_PTR(-ENOMEM);
-
-	state->private_objs = arr;
-	index = state->num_private_objs;
-
 	obj_state = obj->funcs->atomic_duplicate_state(obj);
 	if (!obj_state)
 		return ERR_PTR(-ENOMEM);
 
-	state->private_objs[index].state_to_destroy = obj_state;
-	state->private_objs[index].old_state = obj->state;
-	state->private_objs[index].new_state = obj_state;
-	state->private_objs[index].ptr = obj;
-	obj_state->state = state;
-
-	state->num_private_objs = num_objs;
+	ret = drm_atomic_commit_set_private_obj_state(state, obj, obj_state);
+	if (ret) {
+		obj->funcs->atomic_destroy_state(obj, obj_state);
+		return ERR_PTR(ret);
+	}
 
 	drm_dbg_atomic(state->dev,

-- 
2.55.0

[PATCH v6 09/15] drm/atomic: Create function to insert connector state into a commit

[Maxime Ripard]

drm_atomic_get_connector_state() allocates a new connector state by
duplicating the current one and inserts it into the atomic commit as
a single operation.

However, a later change will need to insert a connector state into a
commit without going through the full allocation and duplication path
in drm_atomic_get_connector_state().

Extract the state insertion logic, including the dynamic array
reallocation, into a new static
drm_atomic_commit_set_connector_state() helper, and convert
drm_atomic_get_connector_state() to use it.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 60 ++++++++++++++++++++++++++++----------------
 1 file changed, 38 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 513e91ad2fdc..81591173265d 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1405,4 +1405,36 @@ drm_atomic_get_new_crtc_for_encoder(struct drm_atomic_commit *state,
 EXPORT_SYMBOL(drm_atomic_get_new_crtc_for_encoder);
 
+static int drm_atomic_commit_set_connector_state(struct drm_atomic_commit *commit,
+						 struct drm_connector *connector,
+						 struct drm_connector_state *connector_state)
+{
+	struct drm_mode_config *config = &connector->dev->mode_config;
+	int index = drm_connector_index(connector);
+
+	drm_modeset_lock_assert_held(&config->connection_mutex);
+
+	if (index >= commit->num_connector) {
+		struct __drm_connnectors_state *c;
+		int alloc = max(index + 1, config->num_connector);
+
+		c = krealloc_array(commit->connectors, alloc,
+				   sizeof(*commit->connectors), GFP_KERNEL | __GFP_ZERO);
+		if (!c)
+			return -ENOMEM;
+
+		commit->connectors = c;
+		commit->num_connector = alloc;
+	}
+
+	drm_connector_get(connector);
+	commit->connectors[index].state_to_destroy = connector_state;
+	commit->connectors[index].old_state = connector->state;
+	commit->connectors[index].new_state = connector_state;
+	commit->connectors[index].ptr = connector;
+	connector_state->state = commit;
+
+	return 0;
+}
+
 /**
  * drm_atomic_get_connector_state - get connector state
@@ -1423,5 +1455,5 @@ drm_atomic_get_connector_state(struct drm_atomic_commit *state,
 			  struct drm_connector *connector)
 {
-	int ret, index;
+	int ret;
 	struct drm_mode_config *config = &connector->dev->mode_config;
 	struct drm_connector_state *connector_state;
@@ -1434,19 +1466,4 @@ drm_atomic_get_connector_state(struct drm_atomic_commit *state,
 		return ERR_PTR(ret);
 
-	index = drm_connector_index(connector);
-
-	if (index >= state->num_connector) {
-		struct __drm_connnectors_state *c;
-		int alloc = max(index + 1, config->num_connector);
-
-		c = krealloc_array(state->connectors, alloc,
-				   sizeof(*state->connectors), GFP_KERNEL | __GFP_ZERO);
-		if (!c)
-			return ERR_PTR(-ENOMEM);
-
-		state->connectors = c;
-		state->num_connector = alloc;
-	}
-
 	connector_state = drm_atomic_get_new_connector_state(state, connector);
 	if (connector_state)
@@ -1457,10 +1474,9 @@ drm_atomic_get_connector_state(struct drm_atomic_commit *state,
 		return ERR_PTR(-ENOMEM);
 
-	drm_connector_get(connector);
-	state->connectors[index].state_to_destroy = connector_state;
-	state->connectors[index].old_state = connector->state;
-	state->connectors[index].new_state = connector_state;
-	state->connectors[index].ptr = connector;
-	connector_state->state = state;
+	ret = drm_atomic_commit_set_connector_state(state, connector, connector_state);
+	if (ret) {
+		connector->funcs->atomic_destroy_state(connector, connector_state);
+		return ERR_PTR(ret);
+	}
 
 	drm_dbg_atomic(connector->dev, "Added [CONNECTOR:%d:%s] %p state to %p\n",

-- 
2.55.0

[PATCH v6 10/15] drm/atomic: Add drm_atomic_implements_create_state() helper

[Maxime Ripard]

The atomic reset path will need to create pristine default states from
scratch for every plane, CRTC, and connector. This requires all of them
to implement the atomic_create_state hook.

Introduce a drm_atomic_implements_create_state() helper that iterates
over all planes, CRTCs, and connectors and returns whether they all
provide the hook. Color operations are excluded since they always use
drm_atomic_helper_colorop_create_state() directly.

This will be used both as a precondition before filling a commit with
default states, and to report the device capability to userspace.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 49 ++++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_atomic.h     |  2 ++
 2 files changed, 51 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 81591173265d..7a77051096c9 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1601,4 +1601,53 @@ drm_atomic_get_new_bridge_state(const struct drm_atomic_commit *state,
 EXPORT_SYMBOL(drm_atomic_get_new_bridge_state);
 
+/**
+ * drm_atomic_implements_create_state - check if a device supports creating pristine states
+ * @dev: DRM device
+ *
+ * Check whether every plane, CRTC, and connector in @dev implements the
+ * &drm_plane_funcs.atomic_create_state, &drm_crtc_funcs.atomic_create_state,
+ * and &drm_connector_funcs.atomic_create_state hooks respectively. These hooks
+ * are required to create default states from scratch rather than duplicating
+ * the current state.
+ *
+ * Color operations are not checked because they always use
+ * drm_atomic_helper_colorop_create_state() and do not have a per-driver hook.
+ *
+ * Returns:
+ * True if all objects implement atomic_create_state, false otherwise.
+ */
+bool drm_atomic_implements_create_state(struct drm_device *dev)
+{
+	struct drm_connector_list_iter conn_iter;
+	struct drm_connector *connector;
+	struct drm_plane *plane;
+	struct drm_crtc *crtc;
+
+	/*
+	 * colorops don't have an atomic_create_state hook but
+	 * drm_atomic_helper_colorop_create_state()
+	 */
+
+	drm_for_each_plane(plane, dev)
+		if (!plane->funcs->atomic_create_state)
+			return false;
+
+	drm_for_each_crtc(crtc, dev)
+		if (!crtc->funcs->atomic_create_state)
+			return false;
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		if (!connector->funcs->atomic_create_state) {
+			drm_connector_list_iter_end(&conn_iter);
+			return false;
+		}
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	return true;
+}
+EXPORT_SYMBOL(drm_atomic_implements_create_state);
+
 /**
  * drm_atomic_add_encoder_bridges - add bridges attached to an encoder
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 3ae35b09c0cf..72c3d420f40c 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -703,4 +703,6 @@ drm_atomic_commit_alloc(struct drm_device *dev);
 void drm_atomic_commit_clear(struct drm_atomic_commit *state);
 
+bool drm_atomic_implements_create_state(struct drm_device *dev);
+
 /**
  * drm_atomic_commit_get - acquire a reference to the atomic state

-- 
2.55.0

[PATCH v6 11/15] drm/atomic: Allow filling a commit with pristine object states

[Maxime Ripard]

The upcoming DRM_MODE_ATOMIC_RESET flag will need to create an atomic
commit that brings the entire device back to a pristine state, as if
no configuration had ever been applied.

Create drm_atomic_commit_fill_with_defaults() which iterates over all
CRTCs, planes, connectors, and color operations in the device and
inserts a fresh default state for each one into the commit. This uses
the atomic_create_state() hooks rather than atomic_duplicate_state(),
since atomic_create_state() provides exactly this pristine state on a
per-object basis.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 142 +++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_ioctl.c  |   1 +
 include/drm/drm_atomic.h     |   2 +
 3 files changed, 145 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 7a77051096c9..c3c38695814f 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1650,4 +1650,146 @@ bool drm_atomic_implements_create_state(struct drm_device *dev)
 EXPORT_SYMBOL(drm_atomic_implements_create_state);
 
+/**
+ * drm_atomic_commit_fill_with_defaults - populate a commit with pristine states
+ * @file_priv: DRM file the reset was requested from, or NULL
+ * @commit: atomic commit to fill
+ *
+ * Iterate over all CRTCs, planes, connectors, and color operations in
+ * the device and insert a freshly created default state for each one
+ * into @commit. The states are created through the atomic_create_state()
+ * hooks, producing the same initial state the driver starts with rather
+ * than a copy of the current hardware state.
+ *
+ * If @file_priv is a lessee, only the CRTCs, planes and connectors part
+ * of its lease are reset, and the other ones are left untouched.
+ * @file_priv is optional: if NULL, it is considered to not hold any
+ * lease, and all objects are reset.
+ *
+ * In the default state, all objects are disabled: CRTCs are inactive,
+ * planes are disabled, and connectors are unbound. Driver-specific
+ * properties such as color pipeline settings or max_bpc may carry
+ * non-zero defaults appropriate for basic display output.
+ *
+ * This is meant to be used with the %DRM_MODE_ATOMIC_RESET flag, which
+ * needs to bring the device back to a known baseline before applying
+ * userspace property changes on top.
+ *
+ * Returns:
+ * 0 on success, or a negative error code on failure.
+ */
+int drm_atomic_commit_fill_with_defaults(struct drm_file *file_priv,
+					 struct drm_atomic_commit *commit)
+{
+	struct drm_device *dev = commit->dev;
+	struct drm_mode_config *config = &dev->mode_config;
+	struct drm_crtc *crtc;
+	struct drm_plane *plane;
+	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+	struct drm_colorop *colorop;
+	int ret;
+
+	drm_WARN_ON(dev, !commit->acquire_ctx);
+
+	/*
+	 * Private objects are ignored because none have userspace
+	 * properties we might want to reset. atomic_check
+	 * implementations will derive or infer their private obj state
+	 * from the state that will end up being committed anyway.
+	 */
+	drm_for_each_colorop(colorop, dev) {
+		struct drm_colorop_state *colorop_state;
+
+		if (!drm_lease_held(file_priv, colorop->plane->base.id))
+			continue;
+
+		ret = drm_modeset_lock(&colorop->plane->mutex, commit->acquire_ctx);
+		if (ret)
+			return ret;
+
+		colorop_state = drm_atomic_helper_colorop_create_state(colorop);
+		if (IS_ERR(colorop_state))
+			return PTR_ERR(colorop_state);
+
+		drm_atomic_commit_set_colorop_state(commit, colorop, colorop_state);
+	}
+
+	drm_for_each_plane(plane, dev) {
+		struct drm_plane_state *plane_state;
+
+		if (!drm_lease_held(file_priv, plane->base.id))
+			continue;
+
+		ret = drm_modeset_lock(&plane->mutex, commit->acquire_ctx);
+		if (ret)
+			return ret;
+
+		plane_state = plane->funcs->atomic_create_state(plane);
+		if (IS_ERR(plane_state))
+			return PTR_ERR(plane_state);
+
+		drm_atomic_commit_set_plane_state(commit, plane, plane_state);
+	}
+
+	drm_for_each_crtc(crtc, dev) {
+		struct drm_crtc_state *crtc_state;
+
+		if (!drm_lease_held(file_priv, crtc->base.id))
+			continue;
+
+		ret = drm_modeset_lock(&crtc->mutex, commit->acquire_ctx);
+		if (ret)
+			return ret;
+
+		crtc_state = crtc->funcs->atomic_create_state(crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+
+		drm_atomic_commit_set_crtc_state(commit, crtc, crtc_state);
+	}
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		struct drm_connector_state *connector_state;
+
+		if (!drm_lease_held(file_priv, connector->base.id))
+			continue;
+
+		ret = drm_modeset_lock(&config->connection_mutex, commit->acquire_ctx);
+		if (ret) {
+			drm_connector_list_iter_end(&conn_iter);
+			return ret;
+		}
+
+		/*
+		 * drm_atomic_implements_create_state() already checked
+		 * this, but connectors can be hotplugged between that
+		 * lockless check and the iteration here.
+		 */
+		if (!connector->funcs->atomic_create_state) {
+			drm_connector_list_iter_end(&conn_iter);
+			return -EOPNOTSUPP;
+		}
+
+		connector_state = connector->funcs->atomic_create_state(connector);
+		if (IS_ERR(connector_state)) {
+			drm_connector_list_iter_end(&conn_iter);
+			ret = PTR_ERR(connector_state);
+			return ret;
+		}
+
+		ret = drm_atomic_commit_set_connector_state(commit, connector, connector_state);
+		if (ret) {
+			connector->funcs->atomic_destroy_state(connector, connector_state);
+			drm_connector_list_iter_end(&conn_iter);
+			return ret;
+		}
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_commit_fill_with_defaults);
+
 /**
  * drm_atomic_add_encoder_bridges - add bridges attached to an encoder
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 9039a39c4324..0dbf04d4aa9e 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -34,4 +34,5 @@
 #include <linux/uaccess.h>
 
+#include <drm/drm_atomic.h>
 #include <drm/drm_auth.h>
 #include <drm/drm_crtc.h>
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 72c3d420f40c..cac74d43a34d 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -704,4 +704,6 @@ void drm_atomic_commit_clear(struct drm_atomic_commit *state);
 
 bool drm_atomic_implements_create_state(struct drm_device *dev);
+int drm_atomic_commit_fill_with_defaults(struct drm_file *file_priv,
+					 struct drm_atomic_commit *commit);
 
 /**

-- 
2.55.0

[PATCH v6 12/15] drm/tests: atomic: Add tests for drm_atomic_commit_fill_with_defaults()

[Maxime Ripard]

drm_atomic_commit_fill_with_defaults() is used by the
DRM_MODE_ATOMIC_RESET flag to bring all objects back to their pristine
state. However, it has no dedicated test coverage.

Add two tests that verify the reset cycle. The first enables a CRTC,
plane, and connector, then calls drm_atomic_commit_fill_with_defaults()
and verifies all objects return to their disabled state: CRTC inactive,
plane disabled with no framebuffer, and connector unbound. The second
goes further and commits the default-filled state to verify the
init -> enable -> reset -> commit sequence completes without errors.

Suggested-by: Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/tests/drm_atomic_test.c | 141 +++++++++++++++++++++++++++++++-
 1 file changed, 139 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_atomic_test.c b/drivers/gpu/drm/tests/drm_atomic_test.c
index 0aca5c1bbeae..a8e21da811aa 100644
--- a/drivers/gpu/drm/tests/drm_atomic_test.c
+++ b/drivers/gpu/drm/tests/drm_atomic_test.c
@@ -143,5 +143,4 @@ static struct kunit_case drm_atomic_get_connector_for_encoder_tests[] = {
 };
 
-
 static struct kunit_suite drm_atomic_get_connector_for_encoder_test_suite = {
 	.name = "drm_test_atomic_get_connector_for_encoder",
@@ -149,5 +148,143 @@ static struct kunit_suite drm_atomic_get_connector_for_encoder_test_suite = {
 };
 
-kunit_test_suite(drm_atomic_get_connector_for_encoder_test_suite);
+/*
+ * Test that after enabling a CRTC and connector, filling with defaults
+ * produces a state where all objects are disabled: CRTC is inactive,
+ * plane is disabled, and connector is unbound.
+ *
+ * This is done without any lease, so all objects are expected to be
+ * reset.
+ *
+ * The plane is not explicitly enabled with a framebuffer here, so
+ * this validates that fill_with_defaults produces a consistent
+ * disabled state rather than testing an active plane teardown.
+ */
+static void drm_test_check_fill_with_defaults(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_connector_state *new_conn_state;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_plane_state *new_plane_state;
+	struct drm_atomic_commit *state;
+	struct drm_display_mode *mode;
+	struct drm_device *drm;
+	int ret;
+
+	priv = create_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm = &priv->drm;
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_enable:
+	ret = drm_kunit_helper_enable_crtc_connector(test, drm,
+						     priv->crtc,
+						     &priv->connector,
+						     mode, &ctx);
+	if (ret == -EDEADLK) {
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_enable;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	ret = drm_atomic_commit_fill_with_defaults(NULL, state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, priv->crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_crtc_state);
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->enable);
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->active);
+
+	new_plane_state = drm_atomic_get_new_plane_state(state, priv->plane);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_plane_state);
+	KUNIT_EXPECT_NULL(test, new_plane_state->crtc);
+	KUNIT_EXPECT_NULL(test, new_plane_state->fb);
+
+	new_conn_state = drm_atomic_get_new_connector_state(state, &priv->connector);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_conn_state);
+	KUNIT_EXPECT_NULL(test, new_conn_state->crtc);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+/*
+ * Test that after enabling a CRTC and connector, fill_with_defaults
+ * produces a state that can be successfully committed.
+ *
+ * This is done without any lease, so all objects are reset.
+ *
+ * The plane is not explicitly enabled with a framebuffer, so this
+ * validates that fill_with_defaults produces a consistent disabled
+ * state rather than testing an active plane teardown.
+ */
+static void drm_test_check_fill_with_defaults_commit(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_commit *state;
+	struct drm_display_mode *mode;
+	struct drm_device *drm;
+	int ret;
+
+	priv = create_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm = &priv->drm;
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_enable:
+	ret = drm_kunit_helper_enable_crtc_connector(test, drm,
+						     priv->crtc,
+						     &priv->connector,
+						     mode, &ctx);
+	if (ret == -EDEADLK) {
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_enable;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	ret = drm_atomic_commit_fill_with_defaults(NULL, state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state->allow_modeset = true;
+
+	ret = drm_atomic_commit(state);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+static struct kunit_case drm_atomic_fill_with_defaults_tests[] = {
+	KUNIT_CASE(drm_test_check_fill_with_defaults),
+	KUNIT_CASE(drm_test_check_fill_with_defaults_commit),
+	{ }
+};
+
+static struct kunit_suite drm_atomic_fill_with_defaults_test_suite = {
+	.name = "drm_atomic_commit_fill_with_defaults",
+	.test_cases = drm_atomic_fill_with_defaults_tests,
+};
+
+kunit_test_suites(&drm_atomic_get_connector_for_encoder_test_suite,
+		  &drm_atomic_fill_with_defaults_test_suite);
 
 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");

-- 
2.55.0

[PATCH v6 13/15] drm/atomic-uapi: Add DRM_MODE_ATOMIC_RESET flag

[Maxime Ripard]

From: Sebastian Wick <sebastian.wick@redhat.com>

Userspace currently has no atomic way to reset all KMS object states
to their defaults. To bring a display pipeline to a known state, a
compositor must explicitly set every property on every object, which
requires tracking which properties exist and what their defaults are.

Introduce DRM_MODE_ATOMIC_RESET (0x0800) which, when passed to the
atomic ioctl, fills the commit with default states for all KMS
objects before applying the properties supplied in the request.
Properties not explicitly included in the commit remain at their
defaults (CRTCs inactive, planes disabled, connectors unbound, and
so on).

The flag cannot be combined with DRM_MODE_PAGE_FLIP_ASYNC, since a
full state reset is incompatible with an async flip.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com>
Co-developed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c      |  3 +++
 drivers/gpu/drm/drm_atomic_uapi.c | 18 ++++++++++++++++++
 drivers/gpu/drm/drm_ioctl.c       |  3 +++
 include/uapi/drm/drm.h            | 10 ++++++++++
 include/uapi/drm/drm_mode.h       | 14 +++++++++++++-
 5 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index c3c38695814f..e7867da2d921 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1614,4 +1614,7 @@ EXPORT_SYMBOL(drm_atomic_get_new_bridge_state);
  * drm_atomic_helper_colorop_create_state() and do not have a per-driver hook.
  *
+ * This is used to report the %DRM_CAP_ATOMIC_RESET capability to userspace,
+ * and as a precondition in drm_atomic_commit_fill_with_defaults().
+ *
  * Returns:
  * True if all objects implement atomic_create_state, false otherwise.
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 1eebcf6f5e05..9ff1ddecb8ed 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1674,4 +1674,11 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
 	}
 
+	if ((arg->flags & DRM_MODE_ATOMIC_RESET) &&
+			(arg->flags & DRM_MODE_PAGE_FLIP_ASYNC)) {
+		drm_dbg_atomic(dev,
+			       "commit failed: reset cannot be combined with async flip\n");
+		return -EINVAL;
+	}
+
 	state = drm_atomic_commit_alloc(dev);
 	if (!state)
@@ -1689,4 +1696,15 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
 	num_fences = 0;
 
+	if (arg->flags & DRM_MODE_ATOMIC_RESET) {
+		if (!drm_atomic_implements_create_state(dev)) {
+			ret = -EOPNOTSUPP;
+			goto out;
+		}
+
+		ret = drm_atomic_commit_fill_with_defaults(file_priv, state);
+		if (ret)
+			goto out;
+	}
+
 	for (i = 0; i < arg->count_objs; i++) {
 		uint32_t obj_id, count_props;
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 0dbf04d4aa9e..e589d93871e2 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -306,4 +306,7 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
 			     dev->mode_config.async_page_flip;
 		break;
+	case DRM_CAP_ATOMIC_RESET:
+		req->value = drm_atomic_implements_create_state(dev);
+		break;
 	default:
 		return -EINVAL;
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index bc7ef7684099..b6e2f2edd122 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -796,4 +796,14 @@ struct drm_gem_change_handle {
 #define DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP	0x15
 
+/**
+ * DRM_CAP_ATOMIC_RESET
+ *
+ * If set to 1, the driver supports the &DRM_MODE_ATOMIC_RESET flag in
+ * &DRM_IOCTL_MODE_ATOMIC commits. When supported, userspace can pass that
+ * flag to reset all KMS object states to their defaults before applying
+ * property changes.
+ */
+#define DRM_CAP_ATOMIC_RESET	0x16
+
 /* DRM_IOCTL_GET_CAP ioctl argument type */
 struct drm_get_cap {
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index ed1a660a3dfd..32eb3f650d7a 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -1329,4 +1329,15 @@ struct drm_mode_destroy_dumb {
  */
 #define DRM_MODE_ATOMIC_ALLOW_MODESET 0x0400
+/**
+ * DRM_MODE_ATOMIC_RESET
+ *
+ * Reset all KMS object states (CRTCs, planes, connectors, color operations)
+ * to their default values before applying the properties in this commit.
+ * Properties not explicitly included in the commit will remain at their
+ * defaults (CRTCs inactive, planes disabled, connectors unbound, etc.).
+ *
+ * This flag cannot be combined with &DRM_MODE_PAGE_FLIP_ASYNC.
+ */
+#define DRM_MODE_ATOMIC_RESET 0x0800
 
 /**
@@ -1341,5 +1352,6 @@ struct drm_mode_destroy_dumb {
 		DRM_MODE_ATOMIC_TEST_ONLY |\
 		DRM_MODE_ATOMIC_NONBLOCK |\
-		DRM_MODE_ATOMIC_ALLOW_MODESET)
+		DRM_MODE_ATOMIC_ALLOW_MODESET |\
+		DRM_MODE_ATOMIC_RESET)
 
 struct drm_mode_atomic {

-- 
2.55.0

[PATCH v6 14/15] drm/vkms: Switch container_of helpers to container_of_const

[Maxime Ripard]

The vkms container_of helpers use container_of() which discards the
const qualifier from the input pointer. This prevents passing a const
state pointer to to_vkms_plane_state() without a cast, for instance
in atomic_get_property which receives a const drm_plane_state.

Switch all four helpers to container_of_const() so the const qualifier
is properly propagated to the result type.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/vkms/vkms_drv.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 381483aa4fb0..dea6cad3f1b9 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -251,14 +251,14 @@ struct vkms_device {
 
 #define drm_crtc_to_vkms_output(target) \
-	container_of(target, struct vkms_output, crtc)
+	container_of_const(target, struct vkms_output, crtc)
 
 #define drm_device_to_vkms_device(target) \
-	container_of(target, struct vkms_device, drm)
+	container_of_const(target, struct vkms_device, drm)
 
 #define to_vkms_crtc_state(target)\
-	container_of(target, struct vkms_crtc_state, base)
+	container_of_const(target, struct vkms_crtc_state, base)
 
 #define to_vkms_plane_state(target)\
-	container_of(target, struct vkms_plane_state, base.base)
+	container_of_const(target, struct vkms_plane_state, base.base)
 
 /**

-- 
2.55.0

[PATCH v6 15/15] drm/vkms: Add driver-specific plane property for testing

[Maxime Ripard]

The DRM_MODE_ATOMIC_RESET flag allows userspace to reset all object
states to their defaults before applying new property values. Testing
that this mechanism works correctly requires a property that the test
can set to a non-default value and then verify is properly reset.

Using a standard property for this is problematic: compositors like
Mutter enumerate and track all known properties, making it difficult
to isolate the reset behavior from the compositor's own property
management.

Add a "vkms-test-do-not-use-in-prod" range property to vkms planes.
The property is stored in vkms_plane_state, duplicated across state
copies, and initialized from its registered default in
atomic_create_state via drm_object_property_get_default_value().

Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/vkms/vkms_drv.h   |  3 ++
 drivers/gpu/drm/vkms/vkms_plane.c | 61 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index dea6cad3f1b9..384616095b45 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -147,4 +147,5 @@ struct conversion_matrix {
  *		     struct vkms_plane_state must ensure that this pointer is valid
  * @conversion_matrix: matrix used for yuv formats to convert to rgb
+ * @vkms_test_do_not_use_value: driver-specific property for testing only
  */
 struct vkms_plane_state {
@@ -153,8 +154,10 @@ struct vkms_plane_state {
 	pixel_read_line_t pixel_read_line;
 	struct conversion_matrix conversion_matrix;
+	unsigned int vkms_test_do_not_use_value;
 };
 
 struct vkms_plane {
 	struct drm_plane base;
+	struct drm_property *vkms_test_do_not_use_property;
 };
 
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index fd3d34dcf0fe..0ebc131c2788 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -12,8 +12,12 @@
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_print.h>
+#include <drm/drm_property.h>
 
 #include "vkms_drv.h"
 #include "vkms_formats.h"
 
+#define to_vkms_plane(target) \
+	container_of_const(target, struct vkms_plane, base)
+
 static const u32 vkms_formats[] = {
 	DRM_FORMAT_ARGB8888,
@@ -55,4 +59,5 @@ static struct drm_plane_state *
 vkms_plane_duplicate_state(struct drm_plane *plane)
 {
+	struct vkms_plane_state *old_state = to_vkms_plane_state(plane->state);
 	struct vkms_plane_state *vkms_state;
 
@@ -61,4 +66,6 @@ vkms_plane_duplicate_state(struct drm_plane *plane)
 		return NULL;
 
+	vkms_state->vkms_test_do_not_use_value = old_state->vkms_test_do_not_use_value;
+
 	__drm_gem_duplicate_shadow_plane_state(plane, &vkms_state->base);
 
@@ -86,5 +93,7 @@ static void vkms_plane_destroy_state(struct drm_plane *plane,
 static struct drm_plane_state *vkms_plane_create_state(struct drm_plane *plane)
 {
+	struct vkms_plane *vkms_plane = to_vkms_plane(plane);
 	struct vkms_plane_state *vkms_state;
+	u64 val;
 
 	vkms_state = kzalloc_obj(*vkms_state);
@@ -96,12 +105,51 @@ static struct drm_plane_state *vkms_plane_create_state(struct drm_plane *plane)
 	__drm_gem_shadow_plane_state_init(plane, &vkms_state->base);
 
+	if (!drm_object_property_get_default_value(&plane->base,
+						   vkms_plane->vkms_test_do_not_use_property,
+						   &val))
+		vkms_state->vkms_test_do_not_use_value = val;
+
 	return &(&vkms_state->base)->base;
 }
 
+static int vkms_plane_atomic_set_property(struct drm_plane *plane,
+					  struct drm_plane_state *state,
+					  struct drm_property *property,
+					  uint64_t val)
+{
+	struct vkms_plane *vkms_plane = to_vkms_plane(plane);
+	struct vkms_plane_state *vkms_state = to_vkms_plane_state(state);
+
+	if (property == vkms_plane->vkms_test_do_not_use_property) {
+		vkms_state->vkms_test_do_not_use_value = val;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int vkms_plane_atomic_get_property(struct drm_plane *plane,
+					  const struct drm_plane_state *state,
+					  struct drm_property *property,
+					  uint64_t *val)
+{
+	const struct vkms_plane_state *vkms_state = to_vkms_plane_state(state);
+	const struct vkms_plane *vkms_plane = to_vkms_plane(plane);
+
+	if (property == vkms_plane->vkms_test_do_not_use_property) {
+		*val = vkms_state->vkms_test_do_not_use_value;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
 static const struct drm_plane_funcs vkms_plane_funcs = {
 	.update_plane		= drm_atomic_helper_update_plane,
 	.disable_plane		= drm_atomic_helper_disable_plane,
-	.atomic_create_state = vkms_plane_create_state,
-	.atomic_duplicate_state = vkms_plane_duplicate_state,
+	.atomic_set_property	= vkms_plane_atomic_set_property,
+	.atomic_get_property	= vkms_plane_atomic_get_property,
+	.atomic_create_state	= vkms_plane_create_state,
+	.atomic_duplicate_state	= vkms_plane_duplicate_state,
 	.atomic_destroy_state	= vkms_plane_destroy_state,
 };
@@ -284,4 +332,13 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
 					  DRM_COLOR_YCBCR_FULL_RANGE);
 
+	plane->vkms_test_do_not_use_property =
+		drm_property_create_range(dev, 0,
+					  "vkms-test-do-not-use-in-prod",
+					  0, U32_MAX);
+	if (plane->vkms_test_do_not_use_property)
+		drm_object_attach_property(&plane->base.base,
+					   plane->vkms_test_do_not_use_property,
+					   0);
+
 	if (vkms_config_plane_get_default_pipeline(plane_cfg))
 		vkms_initialize_colorops(&plane->base);

-- 
2.55.0