[PATCH 33/43] drm/i915: Handle HDCP2.2 downstream topology change

Ramalingam C
2018-02-14T14:21:04Z

When repeater notifies a downstream topology change, this patch
reauthenticate the repeater alone with out disabling the hdcp
encryption. If that fails then complete reauthentication is executed.

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
---
drivers/gpu/drm/i915/intel_hdcp.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index 076a0b0d2ae9..f5e606cc667f 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -1505,9 +1505,23 @@ static int intel_hdcp2_check_link(struct intel_hdcp *hdcp)
goto out;
}

+ if (ret == DRM_HDCP_TOPOLOGY_CHANGE) {
+ if (hdcp->hdcp_value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
+ DRM_DEBUG_KMS("HDCP2.2 Downstream topology change\n");
+ ret = hdcp2_authenticate_repeater_topology(hdcp);
+ if (ret < 0)
+ goto hdcp2_reauth;
+
+ hdcp->hdcp_value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+ schedule_work(&hdcp->hdcp_prop_work);
+ }
+ goto out;
+ }
+
DRM_INFO("[%s:%d] HDCP2.2 link failed, retrying authentication\n",
hdcp->connector->base.name, hdcp->connector->base.base.id);

+hdcp2_reauth:
ret = _intel_hdcp2_disable(hdcp);
if (ret) {
DRM_ERROR("[%s:%d] Failed to disable hdcp2.2 (%d)\n",