One of the last remaining objects to not have its atomic state.
This is being motivated by our attempt to support runtime bus-format
negotiation between elements of the bridge chain.
This patch just paves the road for such a feature by adding a new
drm_bridge_state object inheriting from drm_private_obj so we can
re-use some of the existing state initialization/tracking logic.
v10:
* Add changelog to the commit message
v9:
* Clarify the fact that the bridge->atomic_reset() and
{connector,plane,crtc,...}->reset() semantics are different
* Move the drm_atomic_private_obj_init() call back to
drm_bridge_attach()
* Check the presence of ->atomic_duplicate_state instead of
->atomic_reset in drm_atomic_add_encoder_bridges()
* Fix copy&paste errors in the atomic bridge state helpers doc
* Add A-b/R-b tags
v8:
* Move bridge state helpers out of the CONFIG_DEBUGFS section
v7:
* Move helpers, struct-defs, ... to atomic helper files to avoid the
drm -> drm_kms_helper -> drm circular dep
* Stop providing default implementation for atomic state reset,
duplicate and destroy hooks (has to do with the helper/core split)
* Drop all R-b/T-b as helpers have now be moved to other places
v6:
* Made helpers private, removed doc and moved them to satisfy dependencies
* Renamed helpers to _default_
v5:
* Re-introduced the helpers from v4
v4:
* Fix the doc
* Kill default helpers (inlined)
* Fix drm_atomic_get_bridge_state() to check for an ERR_PTR()
* Add Neil's R-b
v3:
* No changes
v2:
* Use drm_for_each_bridge_in_chain()
* Rename helpers to be more consistent with the rest of the DRM API
* Improve/fix the doc
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/drm_atomic.c | 116 ++++++++++++++++++++++
drivers/gpu/drm/drm_atomic_helper.c | 20 ++++
drivers/gpu/drm/drm_atomic_state_helper.c | 103 +++++++++++++++++++
drivers/gpu/drm/drm_bridge.c | 59 ++++++++++-
include/drm/drm_atomic.h | 34 +++++++
include/drm/drm_atomic_state_helper.h | 13 +++
include/drm/drm_bridge.h | 60 +++++++++++
7 files changed, 400 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index d33691512a8e..65c46ed049c5 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -30,6 +30,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_bridge.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
@@ -1017,6 +1018,121 @@ static void drm_atomic_connector_print_state(struct drm_printer *p,
connector->funcs->atomic_print_state(p, state);
}
+/**
+ * drm_atomic_get_bridge_state - get bridge state
+ * @state: global atomic state object
+ * @bridge: bridge to get state object for
+ *
+ * This function returns the bridge state for the given bridge, allocating it
+ * if needed. It will also grab the relevant bridge lock to make sure that the
+ * state is consistent.
+ *
+ * Returns:
+ *
+ * Either the allocated state or the error code encoded into the pointer. When
+ * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
+ * entire atomic sequence must be restarted.
+ */
+struct drm_bridge_state *
+drm_atomic_get_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge)
+{
+ struct drm_private_state *obj_state;
+
+ obj_state = drm_atomic_get_private_obj_state(state, &bridge->base);
+ if (IS_ERR(obj_state))
+ return ERR_CAST(obj_state);
+
+ return drm_priv_to_bridge_state(obj_state);
+}
+EXPORT_SYMBOL(drm_atomic_get_bridge_state);
+
+/**
+ * drm_atomic_get_old_bridge_state - get old bridge state, if it exists
+ * @state: global atomic state object
+ * @bridge: bridge to grab
+ *
+ * This function returns the old bridge state for the given bridge, or NULL if
+ * the bridge is not part of the global atomic state.
+ */
+struct drm_bridge_state *
+drm_atomic_get_old_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge)
+{
+ struct drm_private_state *obj_state;
+
+ obj_state = drm_atomic_get_old_private_obj_state(state, &bridge->base);
+ if (!obj_state)
+ return NULL;
+
+ return drm_priv_to_bridge_state(obj_state);
+}
+EXPORT_SYMBOL(drm_atomic_get_old_bridge_state);
+
+/**
+ * drm_atomic_get_new_bridge_state - get new bridge state, if it exists
+ * @state: global atomic state object
+ * @bridge: bridge to grab
+ *
+ * This function returns the new bridge state for the given bridge, or NULL if
+ * the bridge is not part of the global atomic state.
+ */
+struct drm_bridge_state *
+drm_atomic_get_new_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge)
+{
+ struct drm_private_state *obj_state;
+
+ obj_state = drm_atomic_get_new_private_obj_state(state, &bridge->base);
+ if (!obj_state)
+ return NULL;
+
+ return drm_priv_to_bridge_state(obj_state);
+}
+EXPORT_SYMBOL(drm_atomic_get_new_bridge_state);
+
+/**
+ * drm_atomic_add_encoder_bridges - add bridges attached to an encoder
+ * @state: atomic state
+ * @encoder: DRM encoder
+ *
+ * This function adds all bridges attached to @encoder. This is needed to add
+ * bridge states to @state and make them available when
+ * &bridge_funcs.atomic_{check,pre_enable,enable,disable_post_disable}() are
+ * called
+ *
+ * Returns:
+ * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
+ * then the w/w mutex code has detected a deadlock and the entire atomic
+ * sequence must be restarted. All other errors are fatal.
+ */
+int
+drm_atomic_add_encoder_bridges(struct drm_atomic_state *state,
+ struct drm_encoder *encoder)
+{
+ struct drm_bridge_state *bridge_state;
+ struct drm_bridge *bridge;
+
+ if (!encoder)
+ return 0;
+
+ DRM_DEBUG_ATOMIC("Adding all bridges for [encoder:%d:%s] to %p\n",
+ encoder->base.id, encoder->name, state);
+
+ drm_for_each_bridge_in_chain(encoder, bridge) {
+ /* Skip bridges that don't implement the atomic state hooks. */
+ if (!bridge->funcs->atomic_duplicate_state)
+ continue;
+
+ bridge_state = drm_atomic_get_bridge_state(state, bridge);
+ if (IS_ERR(bridge_state))
+ return PTR_ERR(bridge_state);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_atomic_add_encoder_bridges);
+
/**
* drm_atomic_add_affected_connectors - add connectors for CRTC
* @state: atomic state
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 4511c2e07bb9..ad8eae98d9e8 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -730,6 +730,26 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
return ret;
}
+ /*
+ * Iterate over all connectors again, and add all affected bridges to
+ * the state.
+ */
+ for_each_oldnew_connector_in_state(state, connector,
+ old_connector_state,
+ new_connector_state, i) {
+ struct drm_encoder *encoder;
+
+ encoder = old_connector_state->best_encoder;
+ ret = drm_atomic_add_encoder_bridges(state, encoder);
+ if (ret)
+ return ret;
+
+ encoder = new_connector_state->best_encoder;
+ ret = drm_atomic_add_encoder_bridges(state, encoder);
+ if (ret)
+ return ret;
+ }
+
ret = mode_valid(state);
if (ret)
return ret;
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index 7cf3cf936547..33141d2cdad4 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -26,6 +26,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_device.h>
@@ -551,3 +552,105 @@ void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj
memcpy(state, obj->state, sizeof(*state));
}
EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
+
+/**
+ * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
+ * @bridge: bridge object
+ * @state: atomic bridge state
+ *
+ * Copies atomic state from a bridge's current state and resets inferred values.
+ * This is useful for drivers that subclass the bridge state.
+ */
+void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ __drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
+ &state->base);
+ state->bridge = bridge;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
+
+/**
+ * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
+ * @bridge: bridge object
+ *
+ * Allocates a new bridge state and initializes it with the current bridge
+ * state values. This helper is meant to be used as a bridge
+ * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
+ * subclass the bridge state.
+ */
+struct drm_bridge_state *
+drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
+{
+ struct drm_bridge_state *new;
+
+ if (WARN_ON(!bridge->base.state))
+ return NULL;
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (new)
+ __drm_atomic_helper_bridge_duplicate_state(bridge, new);
+
+ return new;
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
+
+/**
+ * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
+ * @bridge: the bridge this state refers to
+ * @state: bridge state to destroy
+ *
+ * Destroys a bridge state previously created by
+ * &drm_atomic_helper_bridge_reset() or
+ * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
+ * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
+ * that don't subclass the bridge state.
+ */
+void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
+
+/**
+ * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
+ * default
+ * @bridge: the bridge this state refers to
+ * @state: bridge state to initialize
+ *
+ * Initializes the bridge state to default values. This is meant to be called
+ * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
+ * the bridge state.
+ */
+void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ memset(state, 0, sizeof(*state));
+ state->bridge = bridge;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
+
+/**
+ * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
+ * to its default
+ * @bridge: the bridge this state refers to
+ * @state: bridge state to initialize
+ *
+ * Allocates the bridge state and initializes it to default values. This helper
+ * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
+ * bridges that don't subclass the bridge state.
+ */
+struct drm_bridge_state *
+drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
+{
+ struct drm_bridge_state *bridge_state;
+
+ bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
+ if (!bridge_state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_atomic_helper_bridge_reset(bridge, bridge_state);
+ return bridge_state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index c2cf0c90fa26..6b08158ebb7e 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/mutex.h>
+#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_encoder.h>
@@ -89,6 +90,31 @@ void drm_bridge_remove(struct drm_bridge *bridge)
}
EXPORT_SYMBOL(drm_bridge_remove);
+static struct drm_private_state *
+drm_bridge_atomic_duplicate_priv_state(struct drm_private_obj *obj)
+{
+ struct drm_bridge *bridge = drm_priv_to_bridge(obj);
+ struct drm_bridge_state *state;
+
+ state = bridge->funcs->atomic_duplicate_state(bridge);
+ return state ? &state->base : NULL;
+}
+
+static void
+drm_bridge_atomic_destroy_priv_state(struct drm_private_obj *obj,
+ struct drm_private_state *s)
+{
+ struct drm_bridge_state *state = drm_priv_to_bridge_state(s);
+ struct drm_bridge *bridge = drm_priv_to_bridge(obj);
+
+ bridge->funcs->atomic_destroy_state(bridge, state);
+}
+
+static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = {
+ .atomic_duplicate_state = drm_bridge_atomic_duplicate_priv_state,
+ .atomic_destroy_state = drm_bridge_atomic_destroy_priv_state,
+};
+
/**
* drm_bridge_attach - attach the bridge to an encoder's chain
*
@@ -135,15 +161,35 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
if (bridge->funcs->attach) {
ret = bridge->funcs->attach(bridge);
- if (ret < 0) {
- list_del(&bridge->chain_node);
- bridge->dev = NULL;
- bridge->encoder = NULL;
- return ret;
+ if (ret < 0)
+ goto err_reset_bridge;
+ }
+
+ if (bridge->funcs->atomic_reset) {
+ struct drm_bridge_state *state;
+
+ state = bridge->funcs->atomic_reset(bridge);
+ if (IS_ERR(state)) {
+ ret = PTR_ERR(state);
+ goto err_detach_bridge;
}
+
+ drm_atomic_private_obj_init(bridge->dev, &bridge->base,
+ &state->base,
+ &drm_bridge_priv_state_funcs);
}
return 0;
+
+err_detach_bridge:
+ if (bridge->funcs->detach)
+ bridge->funcs->detach(bridge);
+
+err_reset_bridge:
+ bridge->dev = NULL;
+ bridge->encoder = NULL;
+ list_del(&bridge->chain_node);
+ return ret;
}
EXPORT_SYMBOL(drm_bridge_attach);
@@ -155,6 +201,9 @@ void drm_bridge_detach(struct drm_bridge *bridge)
if (WARN_ON(!bridge->dev))
return;
+ if (bridge->funcs->atomic_reset)
+ drm_atomic_private_obj_fini(&bridge->base);
+
if (bridge->funcs->detach)
bridge->funcs->detach(bridge);
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 951dfb15c27b..82a888769b3d 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -669,6 +669,9 @@ __drm_atomic_get_current_plane_state(struct drm_atomic_state *state,
return plane->state;
}
+int __must_check
+drm_atomic_add_encoder_bridges(struct drm_atomic_state *state,
+ struct drm_encoder *encoder);
int __must_check
drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
struct drm_crtc *crtc);
@@ -992,4 +995,35 @@ drm_atomic_crtc_effectively_active(const struct drm_crtc_state *state)
return state->active || state->self_refresh_active;
}
+/**
+ * struct drm_bridge_state - Atomic bridge state object
+ */
+struct drm_bridge_state {
+ /**
+ * @base: inherit from &drm_private_state
+ */
+ struct drm_private_state base;
+
+ /**
+ * @bridge: the bridge this state refers to
+ */
+ struct drm_bridge *bridge;
+};
+
+static inline struct drm_bridge_state *
+drm_priv_to_bridge_state(struct drm_private_state *priv)
+{
+ return container_of(priv, struct drm_bridge_state, base);
+}
+
+struct drm_bridge_state *
+drm_atomic_get_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge);
+struct drm_bridge_state *
+drm_atomic_get_old_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge);
+struct drm_bridge_state *
+drm_atomic_get_new_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge);
+
#endif /* DRM_ATOMIC_H_ */
diff --git a/include/drm/drm_atomic_state_helper.h b/include/drm/drm_atomic_state_helper.h
index 8171dea4cc22..3f8f1d627f7c 100644
--- a/include/drm/drm_atomic_state_helper.h
+++ b/include/drm/drm_atomic_state_helper.h
@@ -26,6 +26,8 @@
#include <linux/types.h>
+struct drm_bridge;
+struct drm_bridge_state;
struct drm_crtc;
struct drm_crtc_state;
struct drm_plane;
@@ -80,3 +82,14 @@ void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
struct drm_connector_state *state);
void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
struct drm_private_state *state);
+
+void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+struct drm_bridge_state *
+drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge);
+void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+struct drm_bridge_state *
+drm_atomic_helper_bridge_reset(struct drm_bridge *bridge);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 694e153a7531..8883dcfe63cb 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -25,6 +25,8 @@
#include <linux/list.h>
#include <linux/ctype.h>
+
+#include <drm/drm_atomic.h>
#include <drm/drm_encoder.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_modes.h>
@@ -338,6 +340,56 @@ struct drm_bridge_funcs {
*/
void (*atomic_post_disable)(struct drm_bridge *bridge,
struct drm_atomic_state *old_state);
+
+ /**
+ * @atomic_duplicate_state:
+ *
+ * Duplicate the current bridge state object (which is guaranteed to be
+ * non-NULL).
+ *
+ * The atomic_duplicate_state() is optional. When not implemented the
+ * core allocates a drm_bridge_state object and calls
+ * &__drm_atomic_helper_bridge_duplicate_state() to initialize it.
+ *
+ * RETURNS:
+ * A valid drm_bridge_state object or NULL if the allocation fails.
+ */
+ struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
+
+ /**
+ * @atomic_destroy_state:
+ *
+ * Destroy a bridge state object previously allocated by
+ * &drm_bridge_funcs.atomic_duplicate_state().
+ *
+ * The atomic_destroy_state hook is optional. When not implemented the
+ * core calls kfree() on the state.
+ */
+ void (*atomic_destroy_state)(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+
+ /**
+ * @atomic_reset:
+ *
+ * Reset the bridge to a predefined state (or retrieve its current
+ * state) and return a &drm_bridge_state object matching this state.
+ * This function is called at attach time.
+ *
+ * The atomic_reset hook is mandatory if the bridge implements any of
+ * the atomic hooks, and should be left unassigned otherwise.
+ *
+ * Note that the atomic_reset() semantics is not exactly matching the
+ * reset() semantics found on other components (connector, plane, ...).
+ * 1/ The reset operation happens when the bridge is attached, not when
+ * drm_mode_config_reset() is called
+ * 2/ It's meant to be used exclusively on bridges that have been
+ * converted to the ATOMIC API
+ *
+ * RETURNS:
+ * A valid drm_bridge_state object in case of success, an ERR_PTR()
+ * giving the reason of the failure otherwise.
+ */
+ struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
};
/**
@@ -380,6 +432,8 @@ struct drm_bridge_timings {
* struct drm_bridge - central DRM bridge control structure
*/
struct drm_bridge {
+ /** @base: inherit from &drm_private_object */
+ struct drm_private_obj base;
/** @dev: DRM device this bridge belongs to */
struct drm_device *dev;
/** @encoder: encoder to which this bridge is connected */
@@ -404,6 +458,12 @@ struct drm_bridge {
void *driver_private;
};
+static inline struct drm_bridge *
+drm_priv_to_bridge(struct drm_private_obj *priv)
+{
+ return container_of(priv, struct drm_bridge, base);
+}
+
void drm_bridge_add(struct drm_bridge *bridge);
void drm_bridge_remove(struct drm_bridge *bridge);
struct drm_bridge *of_drm_find_bridge(struct device_node *np);
--
2.24.1
