From: Ramalingam C <ramalingam.c@intel.com>
Date: Sat, 3 Feb 2018 03:39:07 +0530
Subject: drm/i915: Optimize HDCP key load
Git-commit: 7ee5798829d2dd95451d844ee8d3cb9a610a0363
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

HDCP key need not be cleared on each hdcp disable. And HDCP key Load
is skipped if key is already loaded.

v2:
  No change. Added Reviewed-by tag.

v3:
  No change.

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1517609350-10698-6-git-send-email-ramalingam.c@intel.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/intel_hdcp.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -49,6 +49,10 @@ static int intel_hdcp_load_keys(struct d
 	int ret;
 	u32 val;
 
+	val = I915_READ(HDCP_KEY_STATUS);
+	if ((val & HDCP_KEY_LOAD_DONE) && (val & HDCP_KEY_LOAD_STATUS))
+		return 0;
+
 	/*
 	 * On HSW and BDW HW loads the HDCP1.4 Key when Display comes
 	 * out of reset. So if Key is not already loaded, its an error state.
@@ -542,8 +546,6 @@ static int _intel_hdcp_disable(struct in
 		return -ETIMEDOUT;
 	}
 
-	intel_hdcp_clear_keys(dev_priv);
-
 	ret = connector->hdcp_shim->toggle_signalling(intel_dig_port, false);
 	if (ret) {
 		DRM_ERROR("Failed to disable HDCP signalling\n");