[Intel-gfx] [PATCH v7 17/17] drm/i915: Add HDCP 1.4 support for MST connectors

Ramalingam C ramalingam.c at intel.com
Thu Jul 9 10:37:12 UTC 2020


On 2020-06-23 at 11:59:07 -0400, Sean Paul wrote:
> From: Sean Paul <seanpaul at chromium.org>
> 
> Now that all the groundwork has been laid, we can turn on HDCP 1.4 over
> MST. Everything except for toggling the HDCP signalling and HDCP 2.2
> support is the same as the DP case, so we'll re-use those callbacks
> 
> Cc: Juston Li <juston.li at intel.com>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>
> Link: https://patchwork.freedesktop.org/patch/msgid/20191203173638.94919-12-sean@poorly.run #v1
> Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-13-sean@poorly.run #v2
> Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-13-sean@poorly.run #v3
> Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-15-sean@poorly.run #v4
> Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-17-sean@poorly.run #v5
> Link: https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-17-sean@poorly.run #v6
> 
> Changes in v2:
> -Toggle HDCP from encoder disable/enable
> -Don't disable HDCP on MST connector destroy, leave that for encoder
>  disable, just ensure the check_work routine isn't running any longer
> Changes in v3:
> -Place the shim in the new intel_dp_hdcp.c file (Ville)
> Changes in v4:
> -Actually use the mst shim for mst connections (Juston)
> -Use QUERY_STREAM_ENC_STATUS MST message to verify channel is encrypted
> Changes in v5:
> -Add sleep on disable signalling to match hdmi delay
> Changes in v6:
> -Disable HDCP over MST on GEN12+ since I'm unsure how it should work and I
>  don't have hardware to test it
> Changes in v7:
> -Remove hdcp2 shims for MST in favor of skipping hdcp2 init (Ramalingam)
> ---
>  drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 66 +++++++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_dp_mst.c  | 18 ++++++
>  drivers/gpu/drm/i915/display/intel_hdcp.c    |  2 +-
>  3 files changed, 84 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> index 43446a6cae8d..3f67bd27fc3c 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> @@ -7,10 +7,12 @@
>   */
>  
>  #include <drm/drm_dp_helper.h>
> +#include <drm/drm_dp_mst_helper.h>
>  #include <drm/drm_hdcp.h>
>  #include <drm/drm_print.h>
>  
>  #include "intel_display_types.h"
> +#include "intel_ddi.h"
>  #include "intel_dp.h"
>  #include "intel_hdcp.h"
>  
> @@ -618,6 +620,65 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
>  	.protocol = HDCP_PROTOCOL_DP,
>  };
>  
> +static int
> +intel_dp_mst_hdcp_toggle_signalling(struct intel_digital_port *intel_dig_port,
> +				    enum transcoder cpu_transcoder,
> +				    bool enable)
> +{
> +	struct drm_i915_private *i915 = to_i915(intel_dig_port->base.base.dev);
> +	int ret;
> +
> +	if (!enable)
> +		usleep_range(6, 60); /* Bspec says >= 6us */
> +
> +	ret = intel_ddi_toggle_hdcp_signalling(&intel_dig_port->base,
> +					       cpu_transcoder, enable);
Sean,

This function toggles the TRANS_DDI_HDCP_SIGNALLING (9th)bit of TRANS_DDI_FUNC_CTL(tran)
But in the hw specification this bit is mentioned to be ignored for non
HDMI/DVI modes of the TRANS DDI.

Any reason why we need this? Did you try with out this function?

Apart from that Patch looks good to me.

-Ram

> +	if (ret)
> +		drm_dbg_kms(&i915->drm, "%s HDCP signalling failed (%d)\n",
> +			      enable ? "Enable" : "Disable", ret);
> +	return ret;
> +}
> +
> +static
> +bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *intel_dig_port,
> +				  struct intel_connector *connector)
> +{
> +	struct drm_i915_private *i915 = to_i915(intel_dig_port->base.base.dev);
> +	struct intel_dp *intel_dp = &intel_dig_port->dp;
> +	struct drm_dp_query_stream_enc_status_ack_reply reply;
> +	int ret;
> +
> +	if (!intel_dp_hdcp_check_link(intel_dig_port, connector))
> +		return false;
> +
> +	ret = drm_dp_send_query_stream_enc_status(&intel_dp->mst_mgr,
> +						  connector->port, &reply);
> +	if (ret) {
> +		drm_dbg_kms(&i915->drm,
> +			    "[CONNECTOR:%d:%s] failed QSES ret=%d\n",
> +			    connector->base.base.id, connector->base.name, ret);
> +		return false;
> +	}
> +
> +	return reply.auth_completed && reply.encryption_enabled;
> +}
> +
> +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,
> +	.read_bstatus = intel_dp_hdcp_read_bstatus,
> +	.repeater_present = intel_dp_hdcp_repeater_present,
> +	.read_ri_prime = intel_dp_hdcp_read_ri_prime,
> +	.read_ksv_ready = intel_dp_hdcp_read_ksv_ready,
> +	.read_ksv_fifo = intel_dp_hdcp_read_ksv_fifo,
> +	.read_v_prime_part = intel_dp_hdcp_read_v_prime_part,
> +	.toggle_signalling = intel_dp_mst_hdcp_toggle_signalling,
> +	.check_link = intel_dp_mst_hdcp_check_link,
> +	.hdcp_capable = intel_dp_hdcp_capable,
> +
> +	.protocol = HDCP_PROTOCOL_DP,
> +};
> +
>  int intel_dp_init_hdcp(struct intel_digital_port *intel_dig_port,
>  		       struct intel_connector *intel_connector)
>  {
> @@ -630,7 +691,10 @@ int intel_dp_init_hdcp(struct intel_digital_port *intel_dig_port,
>  	if (!is_hdcp_supported(dev_priv, port))
>  		return 0;
>  
> -	if (!intel_dp_is_edp(intel_dp))
> +	if (intel_connector->mst_port)
> +		return intel_hdcp_init(intel_connector, port,
> +				       &intel_dp_mst_hdcp_shim);
> +	else if (!intel_dp_is_edp(intel_dp))
>  		return intel_hdcp_init(intel_connector, port,
>  				       &intel_dp_hdcp_shim);
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 0675825dcc20..abaaeeb963d2 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -37,6 +37,7 @@
>  #include "intel_dp.h"
>  #include "intel_dp_mst.h"
>  #include "intel_dpio_phy.h"
> +#include "intel_hdcp.h"
>  
>  static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
>  					    struct intel_crtc_state *crtc_state,
> @@ -352,6 +353,8 @@ static void intel_mst_disable_dp(struct intel_atomic_state *state,
>  	drm_dbg_kms(&i915->drm, "active links %d\n",
>  		    intel_dp->active_mst_links);
>  
> +	intel_hdcp_disable(intel_mst->connector);
> +
>  	drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, connector->port);
>  
>  	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
> @@ -548,6 +551,13 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
>  
>  	if (pipe_config->has_audio)
>  		intel_audio_codec_enable(encoder, pipe_config, conn_state);
> +
> +	/* Enable hdcp if it's desired */
> +	if (conn_state->content_protection ==
> +	    DRM_MODE_CONTENT_PROTECTION_DESIRED)
> +		intel_hdcp_enable(to_intel_connector(conn_state->connector),
> +				  pipe_config->cpu_transcoder,
> +				  (u8)conn_state->hdcp_content_type);
>  }
>  
>  static bool intel_dp_mst_enc_get_hw_state(struct intel_encoder *encoder,
> @@ -770,6 +780,14 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
>  	intel_attach_force_audio_property(connector);
>  	intel_attach_broadcast_rgb_property(connector);
>  
> +
> +	/* TODO: Figure out how to make HDCP work on GEN12+ */
> +	if (INTEL_GEN(dev_priv) < 12) {
> +		ret = intel_dp_init_hdcp(intel_dig_port, intel_connector);
> +		if (ret)
> +			DRM_DEBUG_KMS("HDCP init failed, skipping.\n");
> +	}
> +
>  	/*
>  	 * Reuse the prop from the SST connector because we're
>  	 * not allowed to create new props after device registration.
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 6bd0e4616ee1..ddc9db8de2bc 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -2060,7 +2060,7 @@ int intel_hdcp_init(struct intel_connector *connector,
>  	if (!shim)
>  		return -EINVAL;
>  
> -	if (is_hdcp2_supported(dev_priv))
> +	if (is_hdcp2_supported(dev_priv) && !connector->mst_port)
>  		intel_hdcp2_init(connector, port, shim);
>  
>  	ret =
> -- 
> Sean Paul, Software Engineer, Google / Chromium OS
> 


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