[Intel-gfx] [PATCH v3] drm/i915/hdcp: update HDCP CP property as per port authentication state

[Ramalingam C]

On 2020-01-10 at 19:19:13 +0530, Anshuman Gupta wrote:
> When port is disabled due to modeset crtc disable sequence
> or DPMS off, it eventually disables the HDCP encryption
> keeping its content protection property to CP_ENABLED.
> Since content protection property left at CP_ENABLED by
> mistake, HDCP authentication is not attempted at next DDI
> enable sequence.
> HDCP content property should be updated accordingly
> as per port authentication state.
> 
> v2:
>  - Incorporated the necessary locking. (Ram)
>  - Set content protection property to CP_DESIRED only when
>    user has not asked explicitly to set CP_UNDESIRED.
> 
> v3:
>  - Reset the is_hdcp_undesired flag to false. (Ram)
>  - Rephrasing commit log and small comment for is_hdcp_desired
>    flag. (Ram)
> 
> 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_types.h |  6 ++++++
>  drivers/gpu/drm/i915/display/intel_hdcp.c          | 13 ++++++++++++-
>  2 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 630a94892b7b..a7b4c8324838 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -345,6 +345,12 @@ struct intel_hdcp {
>  	struct delayed_work check_work;
>  	struct work_struct prop_work;
>  
> +	/*
> +	 * Track new_conn CP UNDESIRED state as DDI disable
> +	 * code path does't have access to new conn state.
> +	 */
Can we call it as "Flag to differentiate the HDCP disable originated
from userspace from other disables triggered from kernel."

Apart from that this LGTM. Lets wait for the CI.

Reviewed-by: Ramalingam C <ramalingam.c at intel.com>
> +	bool is_hdcp_undesired;
> +
>  	/* HDCP1.4 Encryption status */
>  	bool hdcp_encrypted;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 0fdbd39f6641..7f631ebd8395 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -2002,11 +2002,18 @@ int intel_hdcp_disable(struct intel_connector *connector)
>  	mutex_lock(&hdcp->mutex);
>  
>  	if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
> -		hdcp->value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
>  		if (hdcp->hdcp2_encrypted)
>  			ret = _intel_hdcp2_disable(connector);
>  		else if (hdcp->hdcp_encrypted)
>  			ret = _intel_hdcp_disable(connector);
> +
> +		if (hdcp->is_hdcp_undesired) {
> +			hdcp->value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
> +			hdcp->is_hdcp_undesired = false;
> +		} else {
> +			hdcp->value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
> +			schedule_work(&hdcp->prop_work);
> +		}
>  	}
>  
>  	mutex_unlock(&hdcp->mutex);
> @@ -2044,6 +2051,7 @@ void intel_hdcp_atomic_check(struct drm_connector *connector,
>  {
>  	u64 old_cp = old_state->content_protection;
>  	u64 new_cp = new_state->content_protection;
> +	struct intel_connector *intel_conn = to_intel_connector(connector);
>  	struct drm_crtc_state *crtc_state;
>  
>  	if (!new_state->crtc) {
> @@ -2069,6 +2077,9 @@ void intel_hdcp_atomic_check(struct drm_connector *connector,
>  			return;
>  	}
>  
> +	if (new_cp == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
> +		intel_conn->hdcp.is_hdcp_undesired  =  true;
> +
>  	crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
>  						   new_state->crtc);
>  	crtc_state->mode_changed = true;
> -- 
> 2.24.0
>