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

[Anshuman Gupta]

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.
+	 */
+	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