[PATCH 25/29] drm/bridge: Provide pointers to the connector and crtc in bridge state

[Maxime Ripard <mripard@kernel.org>]

Now that connectors are no longer necessarily created by the bridges
drivers themselves but might be created by drm_bridge_connector, it's
pretty hard for bridge drivers to retrieve pointers to the connector and
CRTC they are attached to.

Indeed, the only way to retrieve the CRTC is to follow the drm_bridge
encoder field, and then the drm_encoder crtc field, both of them being
deprecated.

And for the connector, since we can have multiple connectors attached to
a CRTC, we don't really have a reliable way to get it.

Let's provide both pointers in the drm_bridge_state structure so we
don't have to follow deprecated, non-atomic, pointers, and be more
consistent with the other KMS entities.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic_state_helper.c |  5 +++++
 drivers/gpu/drm/drm_bridge.c              | 21 +++++++++++++--------
 include/drm/drm_atomic.h                  | 14 ++++++++++++++
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index 519228eb109533d2596e899a57b571fa0995824f..66661dca077215b78dffca7bc1712f56d35e3918 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -777,10 +777,15 @@ EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
  * that don't subclass the bridge state.
  */
 void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
 					    struct drm_bridge_state *state)
 {
+	if (state->connector) {
+		drm_connector_put(state->connector);
+		state->connector = NULL;
+	}
+
 	kfree(state);
 }
 EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
 
 /**
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index c937980d6591fd98e33e37d799ebf84e7e6c5529..069c105aa59636c64caffbefcf482133b0db97d9 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -829,19 +829,24 @@ 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)
 {
+	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;
+
+	bridge_state->crtc = crtc_state->crtc;
+
+	drm_connector_get(conn_state->connector);
+	bridge_state->connector = conn_state->connector;
+
 	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) {
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index bd7959ae312c99c0a0034d36378ae44f04f6a374..b2c5868a3a66280ffc7437fa7a8613079402facd 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -1166,10 +1166,24 @@ struct drm_bridge_state {
 	/**
 	 * @bridge: the bridge this state refers to
 	 */
 	struct drm_bridge *bridge;
 
+	/**
+	 * @crtc: CRTC the bridge is connected to, NULL if disabled.
+	 *
+	 * Do not change this directly.
+	 */
+	struct drm_crtc *crtc;
+
+	/**
+	 * @connector: The connector the bridge is connected to, NULL if disabled.
+	 *
+	 * Do not change this directly.
+	 */
+	struct drm_connector *connector;
+
 	/**
 	 * @input_bus_cfg: input bus configuration
 	 */
 	struct drm_bus_cfg input_bus_cfg;
 

-- 
2.47.1