[PATCH 5/6] drm/atomic: use connector references (v2)

[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.

v2: take Daniel Stone's advice and simplify the
ref/unref dances, also take care of NULL as connector
to state reset.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/drm_atomic.c        | 4 ++++
 drivers/gpu/drm/drm_atomic_helper.c | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 9d5e3c8..91cae88 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1160,6 +1160,8 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 {
 	struct drm_crtc_state *crtc_state;
 
+	if (crtc)
+		drm_connector_reference(conn_state->connector);
 	if (conn_state->crtc && conn_state->crtc != crtc) {
 		crtc_state = drm_atomic_get_existing_crtc_state(conn_state->state,
 								conn_state->crtc);
@@ -1177,6 +1179,8 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 			1 << drm_connector_index(conn_state->connector);
 	}
 
+	if (conn_state->crtc)
+		drm_connector_unreference(conn_state->connector);
 	conn_state->crtc = crtc;
 
 	if (crtc)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d25abce..f3e2642 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 +2891,9 @@ __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 (connector && state->crtc) {
+		drm_connector_unreference(state->connector);
+	}
 }
 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
 
-- 
2.5.5