From f42bb651d1e796ad6d86fc66d578abdee445696b Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 11 Apr 2017 11:13:40 +0100
Subject: [PATCH] drm/i915: Use safer intel_uncore_wait_for_register in ring-init
Git-commit: f42bb651d1e796ad6d86fc66d578abdee445696b
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900

While we do hold the forcewake for legacy ringbuffer initialisation, we
don't guard our access with the uncore.lock spinlock. In theory, we only
initialise when no others should be accessing the same mmio cachelines,
but in practice be safe as this is an infrequently used path and not
worth risky micro-optimisations.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411101340.31994-5-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/intel_ringbuffer.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -538,9 +538,9 @@ static int init_ring_common(struct intel
 	I915_WRITE_CTL(engine, RING_CTL_SIZE(ring->size) | RING_VALID);
 
 	/* If the head is still not zero, the ring is dead */
-	if (intel_wait_for_register_fw(dev_priv, RING_CTL(engine->mmio_base),
-				       RING_VALID, RING_VALID,
-				       50)) {
+	if (intel_wait_for_register(dev_priv, RING_CTL(engine->mmio_base),
+				    RING_VALID, RING_VALID,
+				    50)) {
 		DRM_ERROR("%s initialization failed "
 			  "ctl %08x (valid? %d) head %08x [%08x] tail %08x [%08x] start %08x [expected %08x]\n",
 			  engine->name,