[Intel-gfx] [PATCH] drm/i915: Do uncore early sanitize after domain init

[Mika Kuoppala]

intel_uncore_early_sanitize() will reset the forcewake registers. When
forcewake domains were introduced, the domain init was done after the
sanitization of the forcewake registers. And as the resetting of
registers use the domain accessors, we tried to reset the forcewake
registers with unitialized forcewake domains and failed.

Fix this by sanitizing after all the domains have been initialized.
On ivb we need special care as there we need early forcewake access to
determine the final configuration for the forcewake domain.

This regression was introduced in

commit 05a2fb157e44a53c79133805d30eaada43911941
Author: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Date:   Mon Jan 19 16:20:43 2015 +0200

    drm/i915: Consolidate forcewake code

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88805
Reported-by: Olof Johansson <olof at lixom.net>
Tested-by: Darren Hart <dvhart at linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index b3951f2..c438ca4 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -72,6 +72,7 @@ assert_device_not_suspended(struct drm_i915_private *dev_priv)
 static inline void
 fw_domain_reset(const struct intel_uncore_forcewake_domain *d)
 {
+	WARN_ON(d->reg_set == 0);
 	__raw_i915_write32(d->i915, d->reg_set, d->val_reset);
 }
 
@@ -166,6 +167,8 @@ fw_domains_reset(struct drm_i915_private *dev_priv, enum forcewake_domains fw_do
 	struct intel_uncore_forcewake_domain *d;
 	enum forcewake_domain_id id;
 
+	WARN_ON(dev_priv->uncore.fw_domains == 0);
+
 	for_each_fw_domain_mask(d, fw_domains, dev_priv, id)
 		fw_domain_reset(d);
 
@@ -987,8 +990,7 @@ static void fw_domain_init(struct drm_i915_private *dev_priv,
 void intel_uncore_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	__intel_uncore_early_sanitize(dev, false);
+	bool sanitize_done = false;
 
 	if (IS_GEN9(dev)) {
 		dev_priv->uncore.funcs.force_wake_get = fw_domains_get;
@@ -1037,6 +1039,8 @@ void intel_uncore_init(struct drm_device *dev)
 
 		fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
 			       FORCEWAKE_MT, FORCEWAKE_MT_ACK);
+		__intel_uncore_early_sanitize(dev, false);
+		sanitize_done = true;
 		mutex_lock(&dev->struct_mutex);
 		fw_domains_get_with_thread_status(dev_priv, FORCEWAKE_ALL);
 		ecobus = __raw_i915_read32(dev_priv, ECOBUS);
@@ -1058,6 +1062,9 @@ void intel_uncore_init(struct drm_device *dev)
 			       FORCEWAKE, FORCEWAKE_ACK);
 	}
 
+	if (sanitize_done == false)
+		__intel_uncore_early_sanitize(dev, false);
+
 	switch (INTEL_INFO(dev)->gen) {
 	default:
 		MISSING_CASE(INTEL_INFO(dev)->gen);
-- 
1.9.1