From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 11 May 2018 14:52:07 +0100
Subject: drm/i915/oa: Check that OA is disabled before unpinning
Git-commit: e896d29a548d04371ce746f7d02a8488ff93d812
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Before we unpin the buffer used for OA reports and return it to the
system, we need to be sure that the HW has finished writing into it.
For lack of a better idea, poll OACONTROL to check it is switched off.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106379
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Tested-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180511135207.12880-1-chris@chris-wilson.co.uk

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_perf.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1960,11 +1960,19 @@ static void i915_oa_stream_enable(struct
 static void gen7_oa_disable(struct drm_i915_private *dev_priv)
 {
 	I915_WRITE(GEN7_OACONTROL, 0);
+	if (intel_wait_for_register(dev_priv,
+				    GEN7_OACONTROL, GEN7_OACONTROL_ENABLE, 0,
+				    50))
+		DRM_ERROR("wait for OA to be disabled timed out\n");
 }
 
 static void gen8_oa_disable(struct drm_i915_private *dev_priv)
 {
 	I915_WRITE(GEN8_OACONTROL, 0);
+	if (intel_wait_for_register(dev_priv,
+				    GEN8_OACONTROL, GEN8_OA_COUNTER_ENABLE, 0,
+				    50))
+		DRM_ERROR("wait for OA to be disabled timed out\n");
 }
 
 /**