Commit b86d8955 authored by Boris Brezillon's avatar Boris Brezillon Committed by Neil Armstrong
Browse files

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).

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/20200106143409.32321-4-narmstrong@baylibre.com
parent f7619a58

drivers/gpu/drm/drm_atomic_helper.c

+6 −6
Original line number Diff line number Diff line
@@ -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) {

drivers/gpu/drm/drm_bridge.c

+62 −0
Original line number Diff line number Diff line
@@ -645,6 +645,68 @@ 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 = bridge->encoder;

	struct drm_bridge *iter;



	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);



/**

 * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its

 *					default

include/drm/drm_bridge.h

+28 −1
Original line number Diff line number Diff line
@@ -128,7 +128,9 @@ 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:

	 *
@@ -385,6 +387,28 @@ 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:

	 *
@@ -552,6 +576,9 @@ 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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