[PATCH v4 01/16] drm/i915/hdcp: Update CP property in update_pipe

[Shankar, Uma]

> -----Original Message-----
> From: Anshuman Gupta <anshuman.gupta at intel.com>
> Sent: Tuesday, October 27, 2020 10:12 PM
> To: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org
> Cc: seanpaul at chromium.org; Nikula, Jani <jani.nikula at intel.com>; C,
> Ramalingam <ramalingam.c at intel.com>; Li, Juston <juston.li at intel.com>;
> Shankar, Uma <uma.shankar at intel.com>; Gupta, Anshuman
> <anshuman.gupta at intel.com>
> Subject: [PATCH v4 01/16] drm/i915/hdcp: Update CP property in update_pipe
> 
> When crtc state need_modeset is true it is not necessary it is going to be a real
> modeset, it can turns to be a fastset instead of modeset.
> This turns content protection property to be DESIRED and hdcp update_pipe left
> with property to be in DESIRED state but actual hdcp->value was ENABLED.
> 
> This issue is caught with DP MST setup, where we have multiple connector in
> same DP_MST topology. When disabling HDCP on one of DP MST connector leads
> to set the crtc state need_modeset to true for all other crtc driving the other DP-
> MST topology connectors.
> This turns up other DP MST connectors CP property to be DESIRED despite the
> actual hdcp->value is ENABLED.
> Above scenario fails the DP MST HDCP IGT test, disabling HDCP on one MST
> stream should not cause to disable HDCP on another MST stream on same DP
> MST topology.
> 
> v2:
> Fix WARN_ON(connector->base.registration_state ==
> DRM_CONNECTOR_REGISTERED)
> v3:
> Commit log improvement. [Uma]
> Added a comment before scheduling prop_work. [Uma]

Looks Good to me.
Reviewed-by: Uma Shankar <uma.shankar at intel.com>
 
> Fixes: 33f9a623bfc6 ("drm/i915/hdcp: Update CP as per the kernel internal
> state")
> Cc: Ramalingam C <ramalingam.c at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_hdcp.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index b2a4bbcfdcd2..eee8263405b9 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -2221,6 +2221,14 @@ void intel_hdcp_update_pipe(struct
> intel_atomic_state *state,
>  		desired_and_not_enabled =
>  			hdcp->value !=
> DRM_MODE_CONTENT_PROTECTION_ENABLED;
>  		mutex_unlock(&hdcp->mutex);
> +		/*
> +		 * If HDCP already ENABLED and CP property is DESIRED, schedule
> +		 * prop_work to update correct CP property to user space.
> +		 */
> +		if (!desired_and_not_enabled &&
> !content_protection_type_changed) {
> +			drm_connector_get(&connector->base);
> +			schedule_work(&hdcp->prop_work);
> +		}
>  	}
> 
>  	if (desired_and_not_enabled || content_protection_type_changed)
> --
> 2.26.2