Re: [PATCH 05/11] drm/i915/hdcp: Add new remote capability check shim function

["Nautiyal, Ankit K" <ankit.k.nautiyal@xxxxxxxxx>]

On 2/4/2024 7:54 PM, Suraj Kandpal wrote:
> Create a remote HDCP capability shim function which can read the
> remote monitor HDCP capability when in MST configuration.
>
> --v2
> -Add an assertion to make sure only mst encoder call this remote_cap
> function [Ankit]
>
> Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> ---
>   .../drm/i915/display/intel_display_types.h    |  4 +++
>   drivers/gpu/drm/i915/display/intel_dp_hdcp.c  | 26 +++++++++++++++++++
>   drivers/gpu/drm/i915/display/intel_hdcp.c     | 16 ++++++++++++
>   drivers/gpu/drm/i915/display/intel_hdcp.h     |  3 +++
>   4 files changed, 49 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index ae2e8cff9d69..7e7a370a3b30 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -532,6 +532,10 @@ struct intel_hdcp_shim {
>   	/* HDCP2.2 Link Integrity Check */
>   	int (*check_2_2_link)(struct intel_digital_port *dig_port,
>   			      struct intel_connector *connector);
> +
> +	/* HDCP remote sink cap */
> +	int (*remote_hdcp_cap)(struct intel_connector *connector,
> +			       bool *hdcp_capable, bool *hdcp2_capable);
>   };
>   
>   struct intel_hdcp {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> index ef1a4c90c225..ccd274200f92 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> @@ -668,6 +668,31 @@ int intel_dp_hdcp2_capable(struct intel_connector *connector,
>   	return _intel_dp_hdcp2_capable(aux, capable);
>   }
>   
> +static
> +int intel_dp_hdcp_remote_cap(struct intel_connector *connector,
> +			     bool *hdcp_capable, bool *hdcp2_capable)
> +{
> +	struct drm_i915_private *i915 = to_i915(connector->base.dev);
> +	struct drm_dp_aux *aux = &connector->port->aux;
> +	u8 bcaps;
> +	int ret;
> +
> +	if (!intel_encoder_is_mst(connector->encoder))
> +		return -EINVAL;
> +
> +	ret =  _intel_dp_hdcp2_capable(aux, hdcp2_capable);
> +	if (ret)
> +		return ret;
> +
> +	ret = intel_dp_hdcp_read_bcaps(aux, i915, &bcaps);
> +	if (ret)
> +		return ret;
> +
> +	*hdcp_capable = bcaps & DP_BCAPS_HDCP_CAPABLE;
> +
> +	return 0;
> +}
> +
>   static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
>   	.write_an_aksv = intel_dp_hdcp_write_an_aksv,
>   	.read_bksv = intel_dp_hdcp_read_bksv,
> @@ -685,6 +710,7 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
>   	.config_stream_type = intel_dp_hdcp2_config_stream_type,
>   	.check_2_2_link = intel_dp_hdcp2_check_link,
>   	.hdcp_2_2_capable = intel_dp_hdcp2_capable,
> +	.remote_hdcp_cap = intel_dp_hdcp_remote_cap,
>   	.protocol = HDCP_PROTOCOL_DP,
>   };
>   
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 4593ac10e2fa..2b739249b60c 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -205,6 +205,22 @@ bool intel_hdcp2_capable(struct intel_connector *connector)
>   	return capable;
>   }
>   
> +void intel_hdcp_remote_cap(struct intel_connector *connector,
> +			   bool *hdcp_capable,
> +			   bool *hdcp2_capable)
> +{
> +	struct intel_hdcp *hdcp = &connector->hdcp;
> +
> +	/* Remote Sink's capability for HDCP */

I think we can do away with this comment.

Otherwise looks good to me.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>


> +	if (!hdcp->shim->remote_hdcp_cap)
> +		return;
> +
> +	hdcp->shim->remote_hdcp_cap(connector, hdcp_capable, hdcp2_capable);
> +
> +	if (intel_hdcp2_prerequisite(connector))
> +		*hdcp2_capable = false;
> +}
> +
>   static bool intel_hdcp_in_use(struct drm_i915_private *i915,
>   			      enum transcoder cpu_transcoder, enum port port)
>   {
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.h b/drivers/gpu/drm/i915/display/intel_hdcp.h
> index a9c784fd9ba5..213d286ca3fa 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.h
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
> @@ -40,6 +40,9 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state,
>   bool is_hdcp_supported(struct drm_i915_private *i915, enum port port);
>   bool intel_hdcp_capable(struct intel_connector *connector);
>   bool intel_hdcp2_capable(struct intel_connector *connector);
> +void intel_hdcp_remote_cap(struct intel_connector *connector,
> +			   bool *hdcp_capable,
> +			   bool *hdcp2_capable);
>   void intel_hdcp_component_init(struct drm_i915_private *i915);
>   void intel_hdcp_component_fini(struct drm_i915_private *i915);
>   void intel_hdcp_cleanup(struct intel_connector *connector);