[Intel-gfx] [PATCH 3/2] drm/i915: Add a refcount for the AGPBUSY# bit

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

We can have multiple pipes, but only one AGPBUSY# bit. So we need
a reference correctly figure out whether the bits needs to be set.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h | 3 +++
 drivers/gpu/drm/i915/i915_irq.c | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e908c99..fe4ba16 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1442,6 +1442,9 @@ typedef struct drm_i915_private {
 	u32 hpd_event_bits;
 	struct timer_list hotplug_reenable_timer;
 
+	/* AGPBUSY# wakeup mechanism needed? Gen3 only. */
+	unsigned int agpbusy_ref;
+
 	int num_plane;
 
 	struct i915_fbc fbc;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 0a7a4af..049244b 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2263,7 +2263,7 @@ static int i915_enable_vblank(struct drm_device *dev, int pipe)
 	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
 
 	/* maintain vblank delivery even in deep C-states */
-	if (dev_priv->info->gen == 3)
+	if (dev_priv->info->gen == 3 && dev_priv->agpbusy_ref++ == 0)
 		I915_WRITE(INSTPM, _MASKED_BIT_ENABLE(INSTPM_AGPBUSY_EN));
 
 	if (INTEL_INFO(dev)->gen >= 4)
@@ -2348,7 +2348,7 @@ static void i915_disable_vblank(struct drm_device *dev, int pipe)
 			      PIPE_VBLANK_INTERRUPT_ENABLE |
 			      PIPE_START_VBLANK_INTERRUPT_ENABLE);
 
-	if (dev_priv->info->gen == 3)
+	if (dev_priv->info->gen == 3 && --dev_priv->agpbusy_ref == 0)
 		I915_WRITE(INSTPM, _MASKED_BIT_DISABLE(INSTPM_AGPBUSY_EN));
 
 	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
-- 
1.8.3.2