[PATCH v4 08/11] drm/bridge: Add a drm_bridge_state object
Boris Brezillon
boris.brezillon at collabora.com
Tue Dec 3 14:15:12 UTC 2019
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.
Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
Reviewed-by: Neil Armstrong <narmstrong at baylibre.com>
---
Changes in 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
Changes in v3:
* None
Changes in 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
---
drivers/gpu/drm/drm_atomic.c | 39 +++++++++
drivers/gpu/drm/drm_atomic_helper.c | 20 +++++
drivers/gpu/drm/drm_bridge.c | 118 ++++++++++++++++++++++++++--
include/drm/drm_atomic.h | 3 +
include/drm/drm_bridge.h | 116 +++++++++++++++++++++++++++
5 files changed, 290 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 14aeaf736321..02f8034f5240 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>
@@ -1015,6 +1016,44 @@ static void drm_atomic_connector_print_state(struct drm_printer *p,
connector->funcs->atomic_print_state(p, 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) {
+ 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 29c3115bf9e2..e2f7f336a2d2 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_bridge.c b/drivers/gpu/drm/drm_bridge.c
index b6517b4fa3d1..bf5a2243a115 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 +90,48 @@ 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;
+
+ if (bridge->funcs->atomic_duplicate_state) {
+ state = bridge->funcs->atomic_duplicate_state(bridge);
+
+ return state ? &state->base : NULL;
+ }
+
+ if (WARN_ON(!bridge->base.state))
+ return NULL;
+
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return NULL;
+
+ __drm_atomic_helper_bridge_duplicate_state(bridge, state);
+
+ return &state->base;
+}
+
+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);
+
+ if (bridge->funcs->atomic_destroy_state)
+ bridge->funcs->atomic_destroy_state(bridge, state);
+ else
+ kfree(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
*
@@ -114,6 +157,7 @@ EXPORT_SYMBOL(drm_bridge_remove);
int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
struct drm_bridge *previous)
{
+ struct drm_bridge_state *state;
int ret;
if (!encoder || !bridge)
@@ -135,15 +179,40 @@ 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) {
+ state = bridge->funcs->atomic_reset(bridge);
+ } else {
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ if (state)
+ __drm_atomic_helper_bridge_reset(bridge, state);
+ else
+ state = ERR_PTR(-ENOMEM);
+ }
+
+ 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 +224,8 @@ void drm_bridge_detach(struct drm_bridge *bridge)
if (WARN_ON(!bridge->dev))
return;
+ drm_atomic_private_obj_fini(&bridge->base);
+
if (bridge->funcs->detach)
bridge->funcs->detach(bridge);
@@ -516,6 +587,41 @@ void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
+/**
+ * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
+ * default
+ * @bridge: the bridge this state is refers to
+ * @state: bridge state to initialize
+ *
+ * Initialize the bridge state to default values. This is meant to be* called
+ * by the bridge &drm_plane_funcs.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_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);
+
#ifdef CONFIG_OF
/**
* of_drm_find_bridge - find the bridge corresponding to the device node in
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index b6c73fd9f55a..e08582773d6c 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -660,6 +660,9 @@ __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);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index d7d714023050..db5fc18d49bd 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>
@@ -33,6 +35,23 @@ struct drm_bridge;
struct drm_bridge_timings;
struct drm_panel;
+/**
+ * struct drm_bridge_state - Atomic bridge state object
+ * @base: inherit from &drm_private_state
+ * @bridge: the bridge this state refers to
+ */
+struct drm_bridge_state {
+ struct drm_private_state base;
+
+ 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_funcs - drm_bridge control functions
*/
@@ -338,6 +357,49 @@ 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 optional. When not implemented the core
+ * allocates a new state and calls &__drm_atomic_helper_bridge_reset().
+ *
+ * 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 +442,8 @@ 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 +468,12 @@ 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);
@@ -491,6 +561,52 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
struct drm_atomic_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);
+void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *new);
+
+static inline 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);
+}
+
+static inline 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);
+}
+
+static inline 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);
+}
+
#ifdef CONFIG_DRM_PANEL_BRIDGE
struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
--
2.23.0
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