drm/i915/hdcp: Skip inactive MST connectors when building stream list

intel_hdcp_required_content_stream() walks every connector on the
digital port to populate hdcp_port_data->streams[]. The only filter is
connector_status_disconnected, which reflects physical presence on the
MST topology, not whether the connector currently drives a stream.
On a multi-sink MST setup where only a subset of sinks are modeset,
the loop can pick a sibling MST connector that is connected but has
no active CRTC / VC payload. intel_conn_to_vcpi() then logs "MST
Payload not present" and returns 0, and the bogus StreamID=0 is
written to the repeater in RepeaterAuth_Stream_Manage (DPCD 0x693F0).
Authentication completes, but the repeater shortly raises
LINK_INTEGRITY_FAILURE (RxStatus 0x69493 bit4) because the StreamID
does not match any stream on its input. The HDCP check work then
tears the link down, the Content Protection property drops back to
DESIRED, and userspace observes a spurious HDCP enable failure.
Filter the connector iteration to only those with a CRTC assigned in
the new atomic state, so intel_conn_to_vcpi() is called for the
connector actually being enabled and reads its real VCPI from the MST
topology state.

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Santhosh Reddy Guddati <santhosh.reddy.guddati@intel.com>
Link: https://patch.msgid.link/20260505094022.4064256-1-suraj.kandpal@intel.com

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 982f698e9814..25aca99682fd 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -113,6 +113,7 @@ intel_hdcp_required_content_stream(struct intel_atomic_state *state,
 {
 	struct intel_display *display = to_intel_display(state);
 	struct drm_connector_list_iter conn_iter;
+	struct drm_connector_state *new_conn_state;
 	struct intel_digital_port *conn_dig_port;
 	struct intel_connector *connector;
 	struct hdcp_port_data *data = &dig_port->hdcp.port_data;
@@ -139,6 +140,11 @@ intel_hdcp_required_content_stream(struct intel_atomic_state *state,
 		if (conn_dig_port != dig_port)
 			continue;
 
+		new_conn_state = drm_atomic_get_new_connector_state(&state->base,
+								    &connector->base);
+		if (!new_conn_state || !new_conn_state->crtc)
+			continue;
+
 		data->streams[data->k].stream_id =
 			intel_conn_to_vcpi(state, connector);
 		data->k++;