[PATCH v2 3/5] drm/i915: terminate reauth at stream management failure

Ramalingam C
2020-02-12T10:29:43Z

As per the HDCP2.2 compliance test 1B-10 expectation, when stream
management for a repeater fails, we retry thrice and when it fails
in all retries, HDCP2.2 reauthentication aborted at kernel.

v2:
seq_num_m++ is extended for steam management failures too.[Anshuman]
v3:
use drm_dbg_kms instead of DRM_DEBUG_KMS [Anshuman]
v4:
dev_priv is used as i915 [JaniN]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
---
drivers/gpu/drm/i915/display/intel_hdcp.c | 75 ++++++++++++++---------
1 file changed, 46 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 30e0a3aa9d57..b24d12efae0a 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -1380,7 +1380,7 @@ static int hdcp2_session_key_exchange(struct intel_connector *connector)
}

static
-int hdcp2_propagate_stream_management_info(struct intel_connector *connector)
+int _hdcp2_propagate_stream_management_info(struct intel_connector *connector)
{
struct intel_digital_port *intel_dig_port = intel_attached_dig_port(connector);
struct intel_hdcp *hdcp = &connector->hdcp;
@@ -1406,28 +1406,25 @@ int hdcp2_propagate_stream_management_info(struct intel_connector *connector)
ret = shim->write_2_2_msg(intel_dig_port, &msgs.stream_manage,
sizeof(msgs.stream_manage));
if (ret < 0)
- return ret;
+ goto err_exit;

ret = shim->read_2_2_msg(intel_dig_port, HDCP_2_2_REP_STREAM_READY,
&msgs.stream_ready, sizeof(msgs.stream_ready));
if (ret < 0)
- return ret;
+ goto err_exit;

hdcp->port_data.seq_num_m = hdcp->seq_num_m;
hdcp->port_data.streams[0].stream_type = hdcp->content_type;
-
ret = hdcp2_verify_mprime(connector, &msgs.stream_ready);
- if (ret < 0)
- return ret;

+err_exit:
hdcp->seq_num_m++;
-
if (hdcp->seq_num_m > HDCP_2_2_SEQ_NUM_MAX) {
DRM_DEBUG_KMS("seq_num_m roll over.\n");
- return -1;
+ ret = -1;
}

- return 0;
+ return ret;
}

static
@@ -1492,17 +1489,6 @@ int hdcp2_authenticate_repeater_topology(struct intel_connector *connector)
return 0;
}

-static int hdcp2_authenticate_repeater(struct intel_connector *connector)
-{
- int ret;
-
- ret = hdcp2_authenticate_repeater_topology(connector);
- if (ret < 0)
- return ret;
-
- return hdcp2_propagate_stream_management_info(connector);
-}
-
static int hdcp2_authenticate_sink(struct intel_connector *connector)
{
struct intel_digital_port *intel_dig_port = intel_attached_dig_port(connector);
@@ -1537,18 +1523,13 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
}

if (hdcp->is_repeater) {
- ret = hdcp2_authenticate_repeater(connector);
+ ret = hdcp2_authenticate_repeater_topology(connector);
if (ret < 0) {
DRM_DEBUG_KMS("Repeater Auth Failed. Err: %d\n", ret);
return ret;
}
}

- hdcp->port_data.streams[0].stream_type = hdcp->content_type;
- ret = hdcp2_authenticate_port(connector);
- if (ret < 0)
- return ret;
-
return ret;
}

@@ -1626,14 +1607,50 @@ static int hdcp2_disable_encryption(struct intel_connector *connector)
return ret;
}

+static int
+hdcp2_propagate_stream_management_info(struct intel_connector *connector)
+{
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ int i, tries = 3, ret;
+
+ if (!connector->hdcp.is_repeater)
+ return 0;
+
+ for (i = 0; i < tries; i++) {
+ ret = _hdcp2_propagate_stream_management_info(connector);
+ if (!ret)
+ break;
+
+ drm_dbg_kms(&i915->drm,
+ "HDCP2 stream management %d of %d Failed.(%d)\n",
+ i + 1, tries, ret);
+ }
+
+ return ret;
+}
+
static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
{
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_hdcp *hdcp = &connector->hdcp;
int ret, i, tries = 3;

for (i = 0; i < tries; i++) {
ret = hdcp2_authenticate_sink(connector);
- if (!ret)
- break;
+ if (!ret) {
+ ret = hdcp2_propagate_stream_management_info(connector);
+ if (!ret) {
+ hdcp->port_data.streams[0].stream_type =
+ hdcp->content_type;
+ ret = hdcp2_authenticate_port(connector);
+ if (!ret)
+ break;
+ } else {
+ drm_dbg_kms(&i915->drm,
+ "HDCP2 stream management failed\n");
+ break;
+ }
+ }

/* Clearing the mei hdcp session */
DRM_DEBUG_KMS("HDCP2.2 Auth %d of %d Failed.(%d)\n",
@@ -1642,7 +1659,7 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
DRM_DEBUG_KMS("Port deauth failed.\n");
}

- if (i != tries) {
+ if (!ret) {
/*
* Ensuring the required 200mSec min time interval between
* Session Key Exchange and encryption.
--
2.20.1