[PATCH 1/2] drm/915/hdcp: Use new MST topology state in intel_conn_to_vcpi()

[Suraj Kandpal <suraj.kandpal@intel.com>]

intel_conn_to_vcpi() runs from the HDCP enable path in commit_tail
and looks up the VCPI via mgr->base.state. When an ALLOCATE_PAYLOAD
is being driven on the mgr just before HDCP enable, that payload
list is being mutated in place, so the lookup can miss the port and
trip drm_WARN_ON(!payload), causing HDCP to be programmed with
VCPI 0.
Use drm_atomic_get_new_mst_topology_state() to read the topology
state attached to this atomic commit (stable, decided in
atomic_check), and bail out cleanly when no topology state or
payload is present for this port instead of WARNing.

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 drivers/gpu/drm/i915/display/intel_hdcp.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 9b4ff3b80b05..91d2d7d823cc 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -72,6 +72,7 @@ intel_hdcp_adjust_hdcp_line_rekeying(struct intel_encoder *encoder,
 static int intel_conn_to_vcpi(struct intel_atomic_state *state,
 			      struct intel_connector *connector)
 {
+	struct intel_display *display = to_intel_display(state);
 	struct drm_dp_mst_topology_mgr *mgr;
 	struct drm_dp_mst_atomic_payload *payload;
 	struct drm_dp_mst_topology_state *mst_state;
@@ -82,9 +83,14 @@ static int intel_conn_to_vcpi(struct intel_atomic_state *state,
 	mgr = connector->mst.port->mgr;
 
 	drm_modeset_lock(&mgr->base.lock, state->base.acquire_ctx);
-	mst_state = to_drm_dp_mst_topology_state(mgr->base.state);
+	mst_state = drm_atomic_get_new_mst_topology_state(&state->base, mgr);
+	if (!mst_state) {
+		drm_dbg_kms(display->drm, "MST topology still not created\n");
+		return 0;
+	}
+
 	payload = drm_atomic_get_mst_payload_state(mst_state, connector->mst.port);
-	if (drm_WARN_ON(mgr->dev, !payload))
+	if (!payload)
 		return 0;
 
 	return payload->vcpi;
-- 
2.34.1