Re: [Intel-gfx] [PATCH v8 17/19] drm/i915/hdcp: Support for HDCP 2.2 MST shim callbacks

[Ramalingam C <ramalingam.c@intel.com>]

On 2020-12-11 at 19:12:42 +0530, Anshuman Gupta wrote:
> Add support for HDCP 2.2 DP MST shim callback.
> This adds existing DP HDCP shim callback for Link Authentication
> and Encryption and HDCP 2.2 stream encryption
> callback.
> 
> v2:
> - Added a WARN_ON() instead of drm_err. [Uma]
> - Cosmetic changes. [Uma]
> v3:
> - 's/port_data/hdcp_port_data' [Ram]
> - skip redundant link check. [Ram]
> v4:
> - use pipe instead of port to access HDCP2_STREAM_STATUS
> 
> Cc: Ramalingam C <ramalingam.c@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>

Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
> Tested-by: Karthik B S <karthik.b.s@intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> ---
>  .../drm/i915/display/intel_display_types.h    |  4 +
>  drivers/gpu/drm/i915/display/intel_dp_hdcp.c  | 89 +++++++++++++++++--
>  2 files changed, 85 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 63de25b40eff..da91e3f4ff27 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -378,6 +378,10 @@ struct intel_hdcp_shim {
>  	int (*config_stream_type)(struct intel_digital_port *dig_port,
>  				  bool is_repeater, u8 type);
>  
> +	/* Enable/Disable HDCP 2.2 stream encryption on DP MST Transport Link */
> +	int (*stream_2_2_encryption)(struct intel_connector *connector,
> +				     bool enable);
> +
>  	/* HDCP2.2 Link Integrity Check */
>  	int (*check_2_2_link)(struct intel_digital_port *dig_port,
>  			      struct intel_connector *connector);
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> index 9ade1ad3a80c..f372e25edab4 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> @@ -698,18 +698,14 @@ intel_dp_mst_hdcp_stream_encryption(struct intel_connector *connector,
>  	return 0;
>  }
>  
> -static
> -bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
> -				  struct intel_connector *connector)
> +static bool intel_dp_mst_get_qses_status(struct intel_digital_port *dig_port,
> +					 struct intel_connector *connector)
>  {
>  	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> -	struct intel_dp *intel_dp = &dig_port->dp;
>  	struct drm_dp_query_stream_enc_status_ack_reply reply;
> +	struct intel_dp *intel_dp = &dig_port->dp;
>  	int ret;
>  
> -	if (!intel_dp_hdcp_check_link(dig_port, connector))
> -		return false;
> -
>  	ret = drm_dp_send_query_stream_enc_status(&intel_dp->mst_mgr,
>  						  connector->port, &reply);
>  	if (ret) {
> @@ -726,6 +722,78 @@ bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
>  	return reply.auth_completed && reply.encryption_enabled;
>  }
>  
> +static
> +bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
> +				  struct intel_connector *connector)
> +{
> +	if (!intel_dp_hdcp_check_link(dig_port, connector))
> +		return false;
> +
> +	return intel_dp_mst_get_qses_status(dig_port, connector);
> +}
> +
> +static int
> +intel_dp_mst_hdcp2_stream_encryption(struct intel_connector *connector,
> +				     bool enable)
> +{
> +	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;
> +	enum transcoder cpu_transcoder = hdcp->stream_transcoder;
> +	enum pipe pipe = (enum pipe)cpu_transcoder;
> +	enum port port = dig_port->base.port;
> +	int ret;
> +
> +	drm_WARN_ON(&i915->drm, enable &&
> +		    !!(intel_de_read(i915, HDCP2_AUTH_STREAM(i915, cpu_transcoder, port))
> +		    & AUTH_STREAM_TYPE) != data->streams[0].stream_type);
> +
> +	ret = intel_dp_mst_toggle_hdcp_stream_select(connector, enable);
> +	if (ret)
> +		return ret;
> +
> +	/* Wait for encryption confirmation */
> +	if (intel_de_wait_for_register(i915,
> +				       HDCP2_STREAM_STATUS(i915, cpu_transcoder, pipe),
> +				       STREAM_ENCRYPTION_STATUS,
> +				       enable ? STREAM_ENCRYPTION_STATUS : 0,
> +				       HDCP_ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
> +		drm_err(&i915->drm, "Timed out waiting for transcoder: %s stream encryption %s\n",
> +			transcoder_name(cpu_transcoder), enable ? "enabled" : "disabled");
> +		return -ETIMEDOUT;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * DP v2.0 I.3.3 ignore the stream signature L' in QSES reply msg reply.
> + * I.3.5 MST source device may use a QSES msg to query downstream status
> + * for a particular stream.
> + */
> +static
> +int intel_dp_mst_hdcp2_check_link(struct intel_digital_port *dig_port,
> +				  struct intel_connector *connector)
> +{
> +	struct intel_hdcp *hdcp = &connector->hdcp;
> +	int ret;
> +
> +	/*
> +	 * We do need to do the Link Check only for the connector involved with
> +	 * HDCP port authentication and encryption.
> +	 * We can re-use the hdcp->is_repeater flag to know that the connector
> +	 * involved with HDCP port authentication and encryption.
> +	 */
> +	if (hdcp->is_repeater) {
> +		ret = intel_dp_hdcp2_check_link(dig_port, connector);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return intel_dp_mst_get_qses_status(dig_port, connector) ? 0 : -EINVAL;
> +}
> +
>  static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
>  	.write_an_aksv = intel_dp_hdcp_write_an_aksv,
>  	.read_bksv = intel_dp_hdcp_read_bksv,
> @@ -739,7 +807,12 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
>  	.stream_encryption = intel_dp_mst_hdcp_stream_encryption,
>  	.check_link = intel_dp_mst_hdcp_check_link,
>  	.hdcp_capable = intel_dp_hdcp_capable,
> -
> +	.write_2_2_msg = intel_dp_hdcp2_write_msg,
> +	.read_2_2_msg = intel_dp_hdcp2_read_msg,
> +	.config_stream_type = intel_dp_hdcp2_config_stream_type,
> +	.stream_2_2_encryption = intel_dp_mst_hdcp2_stream_encryption,
> +	.check_2_2_link = intel_dp_mst_hdcp2_check_link,
> +	.hdcp_2_2_capable = intel_dp_hdcp2_capable,
>  	.protocol = HDCP_PROTOCOL_DP,
>  };
>  
> -- 
> 2.26.2
> 
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