[v3,7/8] drm/i915: Reauthenticate HDCP on failure

Commit Message

Ramalingam C Feb. 2, 2018, 10:09 p.m. UTC

Incase of HDCP authentication failure, HDCP spec expects
reauthentication. Hence this patch adds the reauthentications
to be compliance with spec.

v2:
  do-while to for loop for simplicity. [Seanpaul]

v3:
  positioning the logs effectively. [Seanpaul]

Signed-off-by: Ramalingam C <[e-mail]>
---
 drivers/gpu/drm/i915/intel_hdcp.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index 7ae8d83760ed..8f0cf476962f 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -578,7 +578,7 @@  static int _intel_hdcp_disable(struct intel_connector *connector)
 static int _intel_hdcp_enable(struct intel_connector *connector)
 {
 	struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
-	int i, ret;
+	int i, ret, tries = 3;
 
 	DRM_DEBUG_KMS("[%s:%d] HDCP is being enabled...\n",
 		      connector->base.name, connector->base.base.id);
@@ -599,17 +599,21 @@  static int _intel_hdcp_enable(struct intel_connector *connector)
 		return ret;
 	}
 
-	ret = intel_hdcp_auth(conn_to_dig_port(connector),
-			      connector->hdcp_shim);
-	if (ret) {
-		DRM_ERROR("Failed to authenticate HDCP (%d)\n", ret);
+	/* Incase of authentication failures, HDCP spec expects reauth. */
+	for (i = 0; i < tries; i++) {
+		ret = intel_hdcp_auth(conn_to_dig_port(connector),
+				      connector->hdcp_shim);
+		if (!ret)
+			return 0;
+
+		DRM_DEBUG_KMS("HDCP Auth failure (%d)\n", ret);
 
 		/* Ensuring HDCP encryption and signalling are stopped. */
 		_intel_hdcp_disable(connector);
-		return ret;
 	}
 
-	return 0;
+	DRM_ERROR("HDCP authentication failed (%d tries/%d)\n", tries, ret);
+	return ret;
 }
 
 static void intel_hdcp_check_work(struct work_struct *work)