[Intel-gfx] [PATCH 1/4] drm/i915/hdcp: Update CP as per the kernel internal state

[Jani Nikula]

On Tue, 28 Jan 2020, Anshuman Gupta <anshuman.gupta at intel.com> wrote:
> Content Protection property should be updated as per the kernel
> internal state. Let's say if Content protection is disabled
> by userspace, CP property should be set to UNDESIRED so that
> reauthentication will not happen until userspace request it again,
> but when kernel disables the HDCP due to any DDI disabling sequences
> like modeset/DPMS operation, kernel should set the property to
> DESIRED, so that when opportunity arises, kernel will start the
> HDCP authentication on its own.
>
> Somewhere in the line, state machine to set content protection to
> DESIRED from kernel was broken and IGT coverage was missing for it.
> This patch fixes it.
> IGT patch to catch further regression on this features is being
> worked upon.
>
> CC: Ramalingam C <ramalingam.c at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c |  4 +++
>  drivers/gpu/drm/i915/display/intel_hdcp.c    | 26 ++++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_hdcp.h    |  2 ++
>  3 files changed, 32 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index da5266e76738..934cdf1f1858 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -14595,6 +14595,10 @@ static int intel_atomic_check(struct drm_device *dev,
>  		goto fail;
>  
>  	if (any_ms) {
> +		/*
> +		 * When there is modeset fix the hdcp uapi CP state.
> +		 */
> +		intel_hdcp_post_need_modeset_check(state);
>  		ret = intel_modeset_checks(state);
>  		if (ret)
>  			goto fail;
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 0fdbd39f6641..be083136eee2 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -2074,6 +2074,32 @@ void intel_hdcp_atomic_check(struct drm_connector *connector,
>  	crtc_state->mode_changed = true;
>  }
>  
> +/**
> + * intel_hdcp_post_need_modeset_check.
> + * @state: intel atomic state.
> + *
> + * This function fix the HDCP uapi state when hdcp disabling initiated from
> + * modeset DDI disabling sequence. It updates uapi CP state from ENABLED to
> + * DESIRED so that HDCP uapi state can be restored as per HDCP Auth state.
> + * This function should be called only in case of in case of modeset.
> + * FIXME: As per HDCP content protection property uapi doc, an uevent()
> + * need to be sent if there is transition from ENABLED->DESIRED.
> + */
> +void intel_hdcp_post_need_modeset_check(struct intel_atomic_state *state)
> +{
> +	struct drm_connector *connector;
> +	struct drm_connector_state *old_state;
> +	struct drm_connector_state *new_state;
> +	int i;
> +
> +	for_each_oldnew_connector_in_state(&state->base, connector, old_state,
> +					   new_state, i) {
> +		if (old_state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> +		    new_state->content_protection != DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
> +			new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
> +	}
> +}
> +

Why does this feel like duplication of what you already have in
intel_hdcp_atomic_check()?

BR,
Jani.


>  /* Handles the CP_IRQ raised from the DP HDCP sink */
>  void intel_hdcp_handle_cp_irq(struct intel_connector *connector)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.h b/drivers/gpu/drm/i915/display/intel_hdcp.h
> index f3c3272e712a..7bf46bc3c348 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.h
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
> @@ -13,6 +13,7 @@
>  struct drm_connector;
>  struct drm_connector_state;
>  struct drm_i915_private;
> +struct intel_atomic_state;
>  struct intel_connector;
>  struct intel_hdcp_shim;
>  enum port;
> @@ -21,6 +22,7 @@ enum transcoder;
>  void intel_hdcp_atomic_check(struct drm_connector *connector,
>  			     struct drm_connector_state *old_state,
>  			     struct drm_connector_state *new_state);
> +void intel_hdcp_post_need_modeset_check(struct intel_atomic_state *state);
>  int intel_hdcp_init(struct intel_connector *connector,
>  		    const struct intel_hdcp_shim *hdcp_shim);
>  int intel_hdcp_enable(struct intel_connector *connector,

-- 
Jani Nikula, Intel Open Source Graphics Center