[v2,08/20] drm/plane: Add new atomic_create_state callback
Commit Message
Commit 47b5ac7daa46 ("drm/atomic: Add new atomic_create_state callback
to drm_private_obj") introduced a new pattern for allocating drm object
states.
Instead of relying on the reset() callback, it created a new
atomic_create_state hook. This is helpful because reset is a bit
overloaded: it's used to create the initial software state, reset it,
but also reset the hardware.
It can also be used either at probe time, to create the initial state
and possibly reset the hardware to an expected default, but also during
suspend/resume.
Both these cases come with different expectations too: during the
initialization, we want to initialize all states, but during
suspend/resume, drm_private_states for example are expected to be kept
around.
And reset() isn't fallible, which makes it harder to handle
initialization errors properly.
And this is only really relevant for some drivers, since all the helpers
for reset only create a new state, and don't touch the hardware at all.
It was thus decided to create a new hook that would allocate and
initialize a pristine state without any side effect:
atomic_create_state to untangle a bit some of it, and to separate the
initialization with the actual reset one might need during a
suspend/resume.
Let's continue the transition to the new pattern with planes.
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 44 +++++++++++++++++++++++++++++++
drivers/gpu/drm/drm_mode_config.c | 21 ++++++++++++++-
include/drm/drm_atomic_state_helper.h | 4 +++
include/drm/drm_plane.h | 13 +++++++++
4 files changed, 81 insertions(+), 1 deletion(-)
@@ -319,10 +319,29 @@ void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
plane->state = plane_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
+/**
+ * __drm_atomic_helper_plane_create_state - initializes plane state
+ * @plane: plane object
+ * @state: new state to initialize
+ *
+ * Initializes the newly allocated @state, usually required when
+ * initializing the drivers.
+ *
+ * @state is assumed to be zeroed.
+ *
+ * This is useful for drivers that subclass @drm_plane_state.
+ */
+void __drm_atomic_helper_plane_create_state(struct drm_plane *plane,
+ struct drm_plane_state *state)
+{
+ __drm_atomic_helper_plane_state_init(state, plane);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_create_state);
+
/**
* drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
* @plane: drm plane
*
* Resets the atomic state for @plane by freeing the state pointer (which might
@@ -338,10 +357,35 @@ void drm_atomic_helper_plane_reset(struct drm_plane *plane)
if (plane->state)
__drm_atomic_helper_plane_reset(plane, plane->state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
+/**
+ * drm_atomic_helper_plane_create_state - default &drm_plane_funcs.atomic_create_state hook for planes
+ * @plane: plane object
+ *
+ * Initializes a pristine @drm_plane_state.
+ *
+ * This is useful for drivers that don't subclass @drm_plane_state.
+ *
+ * RETURNS:
+ * Pointer to new plane state, or ERR_PTR on failure.
+ */
+struct drm_plane_state *drm_atomic_helper_plane_create_state(struct drm_plane *plane)
+{
+ struct drm_plane_state *state;
+
+ state = kzalloc_obj(*state);
+ if (!state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_atomic_helper_plane_create_state(plane, state);
+
+ return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_create_state);
+
/**
* __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
* @plane: plane object
* @state: atomic plane state
*
@@ -180,10 +180,26 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
drm_connector_list_iter_end(&conn_iter);
return ret;
}
+static int drm_mode_config_plane_create_state(struct drm_plane *plane)
+{
+ struct drm_plane_state *plane_state;
+
+ if (!plane->funcs->atomic_create_state)
+ return 0;
+
+ plane_state = plane->funcs->atomic_create_state(plane);
+ if (IS_ERR(plane_state))
+ return PTR_ERR(plane_state);
+
+ plane->state = plane_state;
+
+ return 0;
+}
+
/**
* drm_mode_config_reset - call ->reset callbacks
* @dev: drm device
*
* This functions calls all the crtc's, encoder's and connector's ->reset
@@ -204,13 +220,16 @@ void drm_mode_config_reset(struct drm_device *dev)
struct drm_connector_list_iter conn_iter;
drm_for_each_colorop(colorop, dev)
drm_colorop_reset(colorop);
- drm_for_each_plane(plane, dev)
+ drm_for_each_plane(plane, dev) {
if (plane->funcs->reset)
plane->funcs->reset(plane);
+ else if (plane->funcs->atomic_create_state)
+ drm_mode_config_plane_create_state(plane);
+ }
drm_for_each_crtc(crtc, dev)
if (crtc->funcs->reset)
crtc->funcs->reset(crtc);
@@ -53,10 +53,14 @@ void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state);
void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
struct drm_crtc_state *state);
void __drm_atomic_helper_plane_state_init(struct drm_plane_state *state,
struct drm_plane *plane);
+void __drm_atomic_helper_plane_create_state(struct drm_plane *plane,
+ struct drm_plane_state *state);
+struct drm_plane_state *
+drm_atomic_helper_plane_create_state(struct drm_plane *plane);
void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
struct drm_plane_state *state);
void drm_atomic_helper_plane_reset(struct drm_plane *plane);
void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
struct drm_plane_state *state);
@@ -386,10 +386,23 @@ struct drm_plane_funcs {
* 0 on success or a negative error code on failure.
*/
int (*set_property)(struct drm_plane *plane,
struct drm_property *property, uint64_t val);
+ /**
+ * @atomic_create_state:
+ *
+ * Allocates a pristine, initialized, state for the plane object
+ * and returns it.
+ *
+ * RETURNS:
+ *
+ * A new, pristine, plane state instance or an error pointer
+ * on failure.
+ */
+ struct drm_plane_state *(*atomic_create_state)(struct drm_plane *plane);
+
/**
* @atomic_duplicate_state:
*
* Duplicate the current atomic state for this plane and return it.
* The core and helpers guarantee that any atomic state duplicated with