[PATCH v8 18/19] drm/i915/hdcp: Configure HDCP2.2 MST steram encryption status

[Ramalingam C]

On 2020-12-11 at 19:12:43 +0530, Anshuman Gupta wrote:
> Authenticate and enable port encryption only once for
> an active HDCP 2.2 session, once port is authenticated
> and encrypted enable encryption for each stream that
> requires encryption on this port.
> 
> Similarly disable the stream encryption for each encrypted
> stream, once all encrypted stream encryption is disabled,
> disable the port HDCP encryption and deauthenticate the port.
> 
> v2:
> - Add connector details in drm_err. [Ram]
> - 's/port_auth/hdcp_auth_status'. [Ram]
> - Added a debug print for stream enc.
> v3:
> - uniformity for connector detail in DMESG. [Ram]
> 
> Cc: Ramalingam C <ramalingam.c at intel.com>
> Reviewed-by: Uma Shankar <uma.shankar at intel.com>
Reviewed-by: Ramalingam C <ramalingam.c at intel.com>
> Tested-by: Karthik B S <karthik.b.s at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_hdcp.c | 51 ++++++++++++++++++++++-
>  1 file changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 2fd8b0453b1d..768a6218b9c4 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -1700,6 +1700,36 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
>  	return ret;
>  }
>  
> +static int hdcp2_enable_stream_encryption(struct intel_connector *connector)
> +{
> +	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> +	struct intel_hdcp *hdcp = &connector->hdcp;
> +	enum transcoder cpu_transcoder = hdcp->cpu_transcoder;
> +	enum port port = dig_port->base.port;
> +	int ret = 0;
> +
> +	if (!(intel_de_read(dev_priv, HDCP2_STATUS(dev_priv, cpu_transcoder, port)) &
> +			    LINK_ENCRYPTION_STATUS)) {
> +		drm_err(&dev_priv->drm, "[%s:%d] HDCP 2.2 Link is not encrypted\n",
> +			connector->base.name, connector->base.base.id);
> +		return -EPERM;
> +	}
> +
> +	if (hdcp->shim->stream_2_2_encryption) {
> +		ret = hdcp->shim->stream_2_2_encryption(connector, true);
> +		if (ret) {
> +			drm_err(&dev_priv->drm, "[%s:%d] Failed to enable HDCP 2.2 stream enc\n",
> +				connector->base.name, connector->base.base.id);
> +			return ret;
> +		}
> +		drm_dbg_kms(&dev_priv->drm, "HDCP 2.2 transcoder: %s stream encrypted\n",
> +			    transcoder_name(hdcp->stream_transcoder));
> +	}
> +
> +	return ret;
> +}
> +
>  static int hdcp2_enable_encryption(struct intel_connector *connector)
>  {
>  	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
> @@ -1838,7 +1868,7 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
>  			drm_dbg_kms(&i915->drm, "Port deauth failed.\n");
>  	}
>  
> -	if (!ret) {
> +	if (!ret && !dig_port->hdcp_auth_status) {
>  		/*
>  		 * Ensuring the required 200mSec min time interval between
>  		 * Session Key Exchange and encryption.
> @@ -1853,6 +1883,8 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
>  		}
>  	}
>  
> +	ret = hdcp2_enable_stream_encryption(connector);
> +
>  	return ret;
>  }
>  
> @@ -1898,11 +1930,26 @@ static int _intel_hdcp2_disable(struct intel_connector *connector)
>  	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
>  	struct drm_i915_private *i915 = to_i915(connector->base.dev);
>  	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
> +	struct intel_hdcp *hdcp = &connector->hdcp;
>  	int ret;
>  
>  	drm_dbg_kms(&i915->drm, "[%s:%d] HDCP2.2 is being Disabled\n",
>  		    connector->base.name, connector->base.base.id);
>  
> +	if (hdcp->shim->stream_2_2_encryption) {
> +		ret = hdcp->shim->stream_2_2_encryption(connector, false);
> +		if (ret) {
> +			drm_err(&i915->drm, "[%s:%d] Failed to disable HDCP 2.2 stream enc\n",
> +				connector->base.name, connector->base.base.id);
> +			return ret;
> +		}
> +		drm_dbg_kms(&i915->drm, "HDCP 2.2 transcoder: %s stream encryption disabled\n",
> +			    transcoder_name(hdcp->stream_transcoder));
> +	}
> +
> +	if (dig_port->num_hdcp_streams > 0)
> +		return ret;
> +
>  	ret = hdcp2_disable_encryption(connector);
>  
>  	if (hdcp2_deauthenticate_port(connector) < 0)
> @@ -1926,6 +1973,7 @@ static int intel_hdcp2_check_link(struct intel_connector *connector)
>  	int ret = 0;
>  
>  	mutex_lock(&hdcp->mutex);
> +	mutex_lock(&dig_port->hdcp_mutex);
>  	cpu_transcoder = hdcp->cpu_transcoder;
>  
>  	/* hdcp2_check_link is expected only when HDCP2.2 is Enabled */
> @@ -2003,6 +2051,7 @@ static int intel_hdcp2_check_link(struct intel_connector *connector)
>  	}
>  
>  out:
> +	mutex_unlock(&dig_port->hdcp_mutex);
>  	mutex_unlock(&hdcp->mutex);
>  	return ret;
>  }
> -- 
> 2.26.2
>