[PATCH 4/5] drm/atomic: use connector references

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

Take a reference when setting a crtc on a connecter,
also take one when duplicating if a crtc is set,
and drop one on destroy if a crtc is set.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/drm_atomic.c        | 11 ++++++++++-
 drivers/gpu/drm/drm_atomic_helper.c |  4 ++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 9d5e3c8..d899dac 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1159,7 +1159,7 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 				  struct drm_crtc *crtc)
 {
 	struct drm_crtc_state *crtc_state;
-
+	bool had_crtc = conn_state->crtc ? true : false;
 	if (conn_state->crtc && conn_state->crtc != crtc) {
 		crtc_state = drm_atomic_get_existing_crtc_state(conn_state->state,
 								conn_state->crtc);
@@ -1179,6 +1179,15 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 
 	conn_state->crtc = crtc;
 
+	/* If we had no crtc then got one, add a reference,
+	 * if we had a crtc and are going to none, drop a reference,
+	 * otherwise just keep the reference we have.
+	 */
+	if (!had_crtc && crtc)
+		drm_connector_reference(conn_state->connector);
+	else if (!crtc && had_crtc)
+		 drm_connector_unreference(conn_state->connector);
+
 	if (crtc)
 		DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
 				 conn_state, crtc->base.id, crtc->name);
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d25abce..a29deac 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2762,6 +2762,8 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
 					    struct drm_connector_state *state)
 {
 	memcpy(state, connector->state, sizeof(*state));
+	if (state->crtc)
+		drm_connector_reference(connector);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
 
@@ -2889,6 +2891,8 @@ __drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 	 * state will automatically do the right thing if code is ever added
 	 * to this function.
 	 */
+	if (state->crtc)
+		drm_connector_unreference(connector);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
 
-- 
2.5.5