RE: [PATCH v8 06/10] drm/i915/hdcp: Retain hdcp_capable return codes

[Kandpal, Suraj]

> -----Original Message-----
> From: Mark Yacoub <markyacoub@xxxxxxxxxxxx>
> Sent: Saturday, April 1, 2023 3:42 AM
> To: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>; Joonas Lahtinen
> <joonas.lahtinen@xxxxxxxxxxxxxxx>; Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx>;
> Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>; David Airlie
> <airlied@xxxxxxxxx>; Daniel Vetter <daniel@xxxxxxxx>
> Cc: seanpaul@xxxxxxxxxxxx; Kandpal, Suraj <suraj.kandpal@xxxxxxxxx>;
> dianders@xxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx;
> freedreno@xxxxxxxxxxxxxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Nikula, Jani
> <jani.nikula@xxxxxxxxx>; Mark Yacoub <markyacoub@xxxxxxxxxxxx>; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH v8 06/10] drm/i915/hdcp: Retain hdcp_capable return codes
> 
> From: Sean Paul <seanpaul@xxxxxxxxxxxx>
> 
> The shim functions return error codes, but they are discarded in
> intel_hdcp.c. This patch plumbs the return codes through so they are
> properly handled.
> 
> Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
> Signed-off-by: Mark Yacoub <markyacoub@xxxxxxxxxxxx>
> 
> ---
> Changes in v2:
> -None
> Changes in v3:
> -None
> Changes in v4:
> -None
> Changes in v5:
> -None
> Changes in v6:
> -Rebased
> Changes in v7:
> -None
> Changes in v8:
> -None
> 
>  .../drm/i915/display/intel_display_debugfs.c  |  9 +++-
>  drivers/gpu/drm/i915/display/intel_hdcp.c     | 51 ++++++++++---------
>  drivers/gpu/drm/i915/display/intel_hdcp.h     |  4 +-
>  3 files changed, 37 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index 7bcd90384a46d..a14b86a07e545 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -494,6 +494,7 @@ static void intel_panel_info(struct seq_file *m,  static
> void intel_hdcp_info(struct seq_file *m,
>  			    struct intel_connector *intel_connector)  {
> +	int ret;
>  	bool hdcp_cap, hdcp2_cap;
> 
>  	if (!intel_connector->hdcp.shim) {
> @@ -501,8 +502,12 @@ static void intel_hdcp_info(struct seq_file *m,
>  		goto out;
>  	}
> 
> -	hdcp_cap = intel_hdcp_capable(intel_connector);
> -	hdcp2_cap = intel_hdcp2_capable(intel_connector);
> +	ret = intel_hdcp_capable(intel_connector, &hdcp_cap);
> +	if (ret)
> +		hdcp_cap = false;
> +	ret = intel_hdcp2_capable(intel_connector, &hdcp2_cap);
> +	if (ret)
> +		hdcp2_cap = false;
> 
>  	if (hdcp_cap)
>  		seq_puts(m, "HDCP1.4 ");
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 0a20bc41be55d..61a862ae1f286 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -177,50 +177,49 @@ int intel_hdcp_read_valid_bksv(struct
> intel_digital_port *dig_port,  }
> 
>  /* Is HDCP1.4 capable on Platform and Sink */ -bool
> intel_hdcp_capable(struct intel_connector *connector)
> +int intel_hdcp_capable(struct intel_connector *connector, bool
> +*capable)
>  {
>  	struct intel_digital_port *dig_port =
> intel_attached_dig_port(connector);
>  	const struct intel_hdcp_shim *shim = connector->hdcp.shim;
> -	bool capable = false;
>  	u8 bksv[5];
> 
> +	*capable = false;
> +
>  	if (!shim)
> -		return capable;
> +		return 0;
> 
> -	if (shim->hdcp_capable) {
> -		shim->hdcp_capable(dig_port, &capable);
> -	} else {
> -		if (!intel_hdcp_read_valid_bksv(dig_port, shim, bksv))
> -			capable = true;
> -	}
> +	if (shim->hdcp_capable)
> +		return shim->hdcp_capable(dig_port, capable);
> +
> +	if (!intel_hdcp_read_valid_bksv(dig_port, shim, bksv))
> +		*capable = true;
> 
> -	return capable;
> +	return 0;
>  }
> 
>  /* Is HDCP2.2 capable on Platform and Sink */ -bool
> intel_hdcp2_capable(struct intel_connector *connector)
> +int intel_hdcp2_capable(struct intel_connector *connector, bool
> +*capable)
>  {
>  	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;
> -	bool capable = false;
> +
> +	*capable = false;
> 
>  	/* I915 support for HDCP2.2 */
>  	if (!hdcp->hdcp2_supported)
> -		return false;
> +		return 0;
> 
>  	/* MEI interface is solid */
>  	mutex_lock(&dev_priv->display.hdcp.comp_mutex);
>  	if (!dev_priv->display.hdcp.comp_added ||  !dev_priv-
> >display.hdcp.master) {
>  		mutex_unlock(&dev_priv->display.hdcp.comp_mutex);
> -		return false;
> +		return 0;
>  	}
>  	mutex_unlock(&dev_priv->display.hdcp.comp_mutex);
> 
>  	/* Sink's capability for HDCP2.2 */
> -	hdcp->shim->hdcp_2_2_capable(dig_port, &capable);
> -
> -	return capable;
> +	return hdcp->shim->hdcp_2_2_capable(dig_port, capable);
>  }
> 
>  static bool intel_hdcp_in_use(struct drm_i915_private *dev_priv, @@ -
> 2355,6 +2354,7 @@ int intel_hdcp_enable(struct intel_connector
> *connector,
>  	struct intel_digital_port *dig_port =
> intel_attached_dig_port(connector);
>  	struct intel_hdcp *hdcp = &connector->hdcp;
>  	unsigned long check_link_interval = DRM_HDCP_CHECK_PERIOD_MS;
> +	bool capable;
>  	int ret = -EINVAL;
> 
>  	if (!hdcp->shim)
> @@ -2373,21 +2373,27 @@ int intel_hdcp_enable(struct intel_connector
> *connector,
>  	 * Considering that HDCP2.2 is more secure than HDCP1.4, If the
> setup
>  	 * is capable of HDCP2.2, it is preferred to use HDCP2.2.
>  	 */
> -	if (intel_hdcp2_capable(connector)) {
> +	ret = intel_hdcp2_capable(connector, &capable);
> +	if (capable) {
>  		ret = _intel_hdcp2_enable(connector);
> -		if (!ret)
> +		if (!ret) {
>  			check_link_interval =
> DRM_HDCP2_CHECK_PERIOD_MS;
> +			goto out;
> +		}
>  	}
> 
>  	/*
>  	 * When HDCP2.2 fails and Content Type is not Type1, HDCP1.4 will
>  	 * be attempted.
>  	 */
> -	if (ret && intel_hdcp_capable(connector) &&
> -	    hdcp->content_type != DRM_MODE_HDCP_CONTENT_TYPE1) {
> +	ret = intel_hdcp_capable(connector, &capable);
> +	if (ret)
> +		goto out;
> +
> +	if (capable && hdcp->content_type !=
> DRM_MODE_HDCP_CONTENT_TYPE1)
>  		ret = _intel_hdcp_enable(connector);
> -	}
> 
> +out:
>  	if (!ret) {
>  		schedule_delayed_work(&hdcp->check_work,
> check_link_interval);
>  		intel_hdcp_update_value(connector,
> @@ -2395,7 +2401,6 @@ int intel_hdcp_enable(struct intel_connector
> *connector,
>  					true);
>  	}

Hi Mark,
These changes here in intel_hdcp_enable are not necessary as this function is getting removed entirely in the
next patch.

With that fixed

Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>

> 
> -out:
>  	mutex_unlock(&dig_port->hdcp_mutex);
>  	mutex_unlock(&hdcp->mutex);
>  	return ret;
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.h
> b/drivers/gpu/drm/i915/display/intel_hdcp.h
> index 7c5fd84a7b65a..f06f6e5a2b1ad 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.h
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
> @@ -33,8 +33,8 @@ void intel_hdcp_update_pipe(struct intel_atomic_state
> *state,
>  			    const struct intel_crtc_state *crtc_state,
>  			    const struct drm_connector_state *conn_state);
> bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port
> port); -bool intel_hdcp_capable(struct intel_connector *connector); -bool
> intel_hdcp2_capable(struct intel_connector *connector);
> +int intel_hdcp_capable(struct intel_connector *connector, bool
> +*capable); int intel_hdcp2_capable(struct intel_connector *connector,
> +bool *capable);
>  void intel_hdcp_component_init(struct drm_i915_private *dev_priv);  void
> intel_hdcp_component_fini(struct drm_i915_private *dev_priv);  void
> intel_hdcp_cleanup(struct intel_connector *connector);
> --
> 2.40.0.348.gf938b09366-goog