From: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date: Tue, 5 Jun 2018 19:03:56 +0300
Subject: drm/i915: Cancel reset preparations on failed resets
Git-commit: c30acb04e7c401d5b412ec925ff4b862bc77b0b8
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Our reset handling has a retry layer further up in the
chain. As we have told the engine to prepare for reset,
and failed it, make sure to remove that preparation so
that the next attempted reset has a clean slate by triggering
another full prepare cycle for the engines.

v2: ret as int, simplified cleanup (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180605160357.32591-1-mika.kuoppala@linux.intel.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/intel_uncore.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -2093,21 +2093,25 @@ static int gen8_reset_engines(struct drm
 {
 	struct intel_engine_cs *engine;
 	unsigned int tmp;
+	int ret;
 
-	for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
-		if (gen8_reset_engine_start(engine))
+	for_each_engine_masked(engine, dev_priv, engine_mask, tmp) {
+		if (gen8_reset_engine_start(engine)) {
+			ret = -EIO;
 			goto not_ready;
+		}
+	}
 
 	if (INTEL_GEN(dev_priv) >= 11)
-		return gen11_reset_engines(dev_priv, engine_mask);
+		ret = gen11_reset_engines(dev_priv, engine_mask);
 	else
-		return gen6_reset_engines(dev_priv, engine_mask);
+		ret = gen6_reset_engines(dev_priv, engine_mask);
 
 not_ready:
 	for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
 		gen8_reset_engine_cancel(engine);
 
-	return -EIO;
+	return ret;
 }
 
 typedef int (*reset_func)(struct drm_i915_private *, unsigned engine_mask);