Commit 5061b8a9 authored by Boris Brezillon's avatar Boris Brezillon

drm/bridge: Add an ->atomic_check() hook

So that bridge drivers have a way to check/reject an atomic operation.
The drm_atomic_bridge_chain_check() (which is just a wrapper around
the ->atomic_check() hook) is called in place of
drm_bridge_chain_mode_fixup() (when ->atomic_check() is not implemented,
the core falls back on ->mode_fixup(), so the behavior should stay
the same for existing bridge drivers).

v10:
* Add changelog to the commit message

v8 -> v9:
* No changes

v7:
* Fix a NULL pointer dereference

v5 -> v6:
* No changes

v4:
* Add R-bs

v3:
* No changes

v2:
* Clarify the fact that ->atomic_check() is replacing ->mode_fixup()
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Reviewed by: Jernej Skrabec <jernej.skrabec@siol.net>
Tested-by: default avatarJonas Karlman <jonas@kwiboo.se>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128135514.108171-6-boris.brezillon@collabora.com
parent 41cf5712
......@@ -437,12 +437,12 @@ mode_fixup(struct drm_atomic_state *state)
funcs = encoder->helper_private;
bridge = drm_bridge_chain_get_first_bridge(encoder);
ret = drm_bridge_chain_mode_fixup(bridge,
&new_crtc_state->mode,
&new_crtc_state->adjusted_mode);
if (!ret) {
DRM_DEBUG_ATOMIC("Bridge fixup failed\n");
return -EINVAL;
ret = drm_atomic_bridge_chain_check(bridge,
new_crtc_state,
new_conn_state);
if (ret) {
DRM_DEBUG_ATOMIC("Bridge atomic check failed\n");
return ret;
}
if (funcs && funcs->atomic_check) {
......
......@@ -602,6 +602,72 @@ void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
static int drm_atomic_bridge_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
{
if (bridge->funcs->atomic_check) {
struct drm_bridge_state *bridge_state;
int ret;
bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
bridge);
if (WARN_ON(!bridge_state))
return -EINVAL;
ret = bridge->funcs->atomic_check(bridge, bridge_state,
crtc_state, conn_state);
if (ret)
return ret;
} else if (bridge->funcs->mode_fixup) {
if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,
&crtc_state->adjusted_mode))
return -EINVAL;
}
return 0;
}
/**
* drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
* @bridge: bridge control structure
* @crtc_state: new CRTC state
* @conn_state: new connector state
*
* Calls &drm_bridge_funcs.atomic_check() (falls back on
* &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
* starting from the last bridge to the first. These are called before calling
* &drm_encoder_helper_funcs.atomic_check()
*
* RETURNS:
* 0 on success, a negative error code on failure
*/
int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
{
struct drm_encoder *encoder;
struct drm_bridge *iter;
if (!bridge)
return 0;
encoder = bridge->encoder;
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
int ret;
ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);
if (ret)
return ret;
if (iter == bridge)
break;
}
return 0;
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
#ifdef CONFIG_OF
/**
* of_drm_find_bridge - find the bridge corresponding to the device node in
......
......@@ -111,7 +111,9 @@ struct drm_bridge_funcs {
* this function passes all other callbacks must succeed for this
* configuration.
*
* The @mode_fixup callback is optional.
* The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
* is not called when &drm_bridge_funcs.atomic_check() is implemented,
* so only one of them should be provided.
*
* NOTE:
*
......@@ -368,6 +370,28 @@ struct drm_bridge_funcs {
void (*atomic_destroy_state)(struct drm_bridge *bridge,
struct drm_bridge_state *state);
/**
* @atomic_check:
*
* This method is responsible for checking bridge state correctness.
* It can also check the state of the surrounding components in chain
* to make sure the whole pipeline can work properly.
*
* &drm_bridge_funcs.atomic_check() hooks are called in reverse
* order (from the last to the first bridge).
*
* This method is optional. &drm_bridge_funcs.mode_fixup() is not
* called when &drm_bridge_funcs.atomic_check() is implemented, so only
* one of them should be provided.
*
* RETURNS:
* zero if the check passed, a negative error code otherwise.
*/
int (*atomic_check)(struct drm_bridge *bridge,
struct drm_bridge_state *bridge_state,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state);
/**
* @atomic_reset:
*
......@@ -542,6 +566,9 @@ void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
void drm_bridge_chain_pre_enable(struct drm_bridge *bridge);
void drm_bridge_chain_enable(struct drm_bridge *bridge);
int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state);
void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
struct drm_atomic_state *state);
void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
......
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