HDCP Repeater initializes seq_num_V to 0 at the beginning of
hdcp Session i.e. after AKE_init received, refer
HDCP 2.2 Spec HDMI PAGE 19, DP PAGE 20.

HDCP 2.2 Comp specs 1B-06 test verifies that whether DUT
considers failure of authentication if the repeater provides a
non-zero value in seq_num_V in the first,
RepeaterAuth_Send_ReceiverID_List message.

Make sure that HDCP repeater initializes seq_num_V to zero at
beginning of session i.e. after AKE_Init, fail the Auth if
there is non zero seq_num_V.

v2:
- Used existing hdcp2_encrypted flag instead of
  declaring new flag. [Ram]

Cc: Ramalingam C <ramalinga...@intel.com>
Reviewed-by: Ramalingam C <ramalinga...@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gu...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_hdcp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c 
b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 30e0a3aa9d57..75f60ca282fc 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -1462,6 +1462,12 @@ int hdcp2_authenticate_repeater_topology(struct 
intel_connector *connector)
        seq_num_v =
                drm_hdcp_be24_to_cpu((const u8 *)msgs.recvid_list.seq_num_v);
 
+       if (!hdcp->hdcp2_encrypted && seq_num_v) {
+               drm_dbg_kms(&dev_priv->drm,
+                           "Non zero Seq_num_v at first RecvId_List msg\n");
+               return -EINVAL;
+       }
+
        if (seq_num_v < hdcp->seq_num_v) {
                /* Roll over of the seq_num_v from repeater. Reauthenticate. */
                DRM_DEBUG_KMS("Seq_num_v roll over.\n");
-- 
2.24.0

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to