Merge remote-tracking branch 'airlied/drm-fixes' into drm-intel-next-queued

Back-merge from drm-fixes into drm-intel-next to sort out two things:

- interlaced support: -fixes contains a bugfix to correctly clear
  interlaced configuration bits in case the bios sets up an interlaced
  mode and we want to set up the progressive mode (current kernels
  don't support interlaced). The actual feature work to support
  interlaced depends upon (and conflicts with) this bugfix.

- forcewake voodoo to workaround missed IRQ issues: -fixes only enabled
  this for ivybridge, but some recent bug reports indicate that we
  need this on Sandybridge, too. But in a slightly different flavour
  and with other fixes and reworks on top. Additionally there are some
  forcewake cleanup patches heading to -next that would conflict with
  currrent -fixes.

Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 44 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index d92c92dea4ec..189041984aba 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -377,11 +377,12 @@ void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)
  */
 void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
 {
-	WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
+	unsigned long irqflags;
 
-	/* Forcewake is atomic in case we get in here without the lock */
-	if (atomic_add_return(1, &dev_priv->forcewake_count) == 1)
+	spin_lock_irqsave(&dev_priv->gt_lock, irqflags);
+	if (dev_priv->forcewake_count++ == 0)
 		dev_priv->display.force_wake_get(dev_priv);
+	spin_unlock_irqrestore(&dev_priv->gt_lock, irqflags);
 }
 
 void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
@@ -401,10 +402,12 @@ void __gen6_gt_force_wake_mt_put(struct drm_i915_private *dev_priv)
  */
 void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
 {
-	WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
+	unsigned long irqflags;
 
-	if (atomic_dec_and_test(&dev_priv->forcewake_count))
+	spin_lock_irqsave(&dev_priv->gt_lock, irqflags);
+	if (--dev_priv->forcewake_count == 0)
 		dev_priv->display.force_wake_put(dev_priv);
+	spin_unlock_irqrestore(&dev_priv->gt_lock, irqflags);
 }
 
 void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
@@ -606,9 +609,36 @@ static int ironlake_do_reset(struct drm_device *dev, u8 flags)
 static int gen6_do_reset(struct drm_device *dev, u8 flags)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	int	ret;
+	unsigned long irqflags;
 
-	I915_WRITE(GEN6_GDRST, GEN6_GRDOM_FULL);
-	return wait_for((I915_READ(GEN6_GDRST) & GEN6_GRDOM_FULL) == 0, 500);
+	/* Hold gt_lock across reset to prevent any register access
+	 * with forcewake not set correctly
+	 */
+	spin_lock_irqsave(&dev_priv->gt_lock, irqflags);
+
+	/* Reset the chip */
+
+	/* GEN6_GDRST is not in the gt power well, no need to check
+	 * for fifo space for the write or forcewake the chip for
+	 * the read
+	 */
+	I915_WRITE_NOTRACE(GEN6_GDRST, GEN6_GRDOM_FULL);
+
+	/* Spin waiting for the device to ack the reset request */
+	ret = wait_for((I915_READ_NOTRACE(GEN6_GDRST) & GEN6_GRDOM_FULL) == 0, 500);
+
+	/* If reset with a user forcewake, try to restore, otherwise turn it off */
+	if (dev_priv->forcewake_count)
+		dev_priv->display.force_wake_get(dev_priv);
+	else
+		dev_priv->display.force_wake_put(dev_priv);
+
+	/* Restore fifo count */
+	dev_priv->gt_fifo_count = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
+
+	spin_unlock_irqrestore(&dev_priv->gt_lock, irqflags);
+	return ret;
 }
 
 /**
@@ -652,9 +682,6 @@ int i915_reset(struct drm_device *dev, u8 flags)
 	case 7:
 	case 6:
 		ret = gen6_do_reset(dev, flags);
-		/* If reset with a user forcewake, try to restore */
-		if (atomic_read(&dev_priv->forcewake_count))
-			__gen6_gt_force_wake_get(dev_priv);
 		break;
 	case 5:
 		ret = ironlake_do_reset(dev, flags);
@@ -940,9 +967,14 @@ MODULE_LICENSE("GPL and additional rights");
 u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
 	u##x val = 0; \
 	if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
-		gen6_gt_force_wake_get(dev_priv); \
+		unsigned long irqflags; \
+		spin_lock_irqsave(&dev_priv->gt_lock, irqflags); \
+		if (dev_priv->forcewake_count == 0) \
+			dev_priv->display.force_wake_get(dev_priv); \
 		val = read##y(dev_priv->regs + reg); \
-		gen6_gt_force_wake_put(dev_priv); \
+		if (dev_priv->forcewake_count == 0) \
+			dev_priv->display.force_wake_put(dev_priv); \
+		spin_unlock_irqrestore(&dev_priv->gt_lock, irqflags); \
 	} else { \
 		val = read##y(dev_priv->regs + reg); \
 	} \