drm/i915: Clear FORCEWAKE when taking over from BIOS
Some BIOSes may forcibly suspend RC6 during their operation which
trigger a warning as we find the hardware in a perplexing state upon
first use. So far that appears to be the worst symptom as fortuituously
we use the same values as the BIOS for programming the FORCEWAKE register.
Reported-by: Oleksij Rempel <bug-track@fisher-privat.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 9c779c6..2b3cddf 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3965,6 +3965,12 @@
DRM_ERROR("GT thread status wait timed out\n");
}
+static void __gen6_gt_force_wake_reset(struct drm_i915_private *dev_priv)
+{
+ I915_WRITE_NOTRACE(FORCEWAKE, 0);
+ POSTING_READ(ECOBUS); /* something from same cacheline, but !FORCEWAKE */
+}
+
static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
{
u32 forcewake_ack;
@@ -3988,6 +3994,12 @@
__gen6_gt_wait_for_thread_c0(dev_priv);
}
+static void __gen6_gt_force_wake_mt_reset(struct drm_i915_private *dev_priv)
+{
+ I915_WRITE_NOTRACE(FORCEWAKE_MT, _MASKED_BIT_DISABLE(0xffff));
+ POSTING_READ(ECOBUS); /* something from same cacheline, but !FORCEWAKE */
+}
+
static void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)
{
u32 forcewake_ack;
@@ -4083,6 +4095,11 @@
return ret;
}
+static void vlv_force_wake_reset(struct drm_i915_private *dev_priv)
+{
+ I915_WRITE_NOTRACE(FORCEWAKE_VLV, _MASKED_BIT_DISABLE(0xffff));
+}
+
static void vlv_force_wake_get(struct drm_i915_private *dev_priv)
{
if (wait_for_atomic((I915_READ_NOTRACE(FORCEWAKE_ACK_VLV) & 1) == 0,
@@ -4105,12 +4122,27 @@
gen6_gt_check_fifodbg(dev_priv);
}
+void intel_gt_reset(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ if (IS_VALLEYVIEW(dev)) {
+ vlv_force_wake_reset(dev_priv);
+ } else if (INTEL_INFO(dev)->gen >= 6) {
+ __gen6_gt_force_wake_reset(dev_priv);
+ if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev))
+ __gen6_gt_force_wake_mt_reset(dev_priv);
+ }
+}
+
void intel_gt_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
spin_lock_init(&dev_priv->gt_lock);
+ intel_gt_reset(dev);
+
if (IS_VALLEYVIEW(dev)) {
dev_priv->gt.force_wake_get = vlv_force_wake_get;
dev_priv->gt.force_wake_put = vlv_force_wake_put;