[Intel-gfx] [PATCH v2 8/8] drm/i915: Use the vblank power domain disallow or disable DC states.

[Dhinakaran Pandiyan]

Disable DC states before enabling vblank interrupts and conversely
enable DC states after disabling. Since the frame counter may have got
reset between disabling and enabling, use drm_crtc_vblank_restore() to
compute the missed vblanks.

Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 3517c6548e2c..88b4ceac55d0 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2963,6 +2963,11 @@ static int gen8_enable_vblank(struct drm_device *dev, unsigned int pipe)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	unsigned long irqflags;
+	bool needs_restore = false;
+
+	intel_display_power_vblank_get(dev_priv, &needs_restore);
+	if (needs_restore)
+		drm_crtc_vblank_restore(dev, pipe);
 
 	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
 	bdw_enable_pipe_irq(dev_priv, pipe, GEN8_PIPE_VBLANK);
@@ -3015,6 +3020,7 @@ static void gen8_disable_vblank(struct drm_device *dev, unsigned int pipe)
 	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
 	bdw_disable_pipe_irq(dev_priv, pipe, GEN8_PIPE_VBLANK);
 	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+	intel_display_power_vblank_put(dev_priv);
 }
 
 static void ibx_irq_reset(struct drm_i915_private *dev_priv)
-- 
2.11.0