drm/i915: disable interrupts when enabling PC8

The plan is to merge PC8 and D3 into a single feature, and when we're
in D3 we won't get any hotplug interrupt anyway, so leaving them
enable doesn't make sense, and it also brings us a problem. The
problem is that we get a hotplug interrupt right when we we wake up
from D3, when we're still waking up everything. If we fully disable
interrupts we won't get this hotplug interrupt, so we won't have
problems.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -3900,8 +3900,8 @@ void hsw_pc8_disable_interrupts(struct drm_device *dev)
 	dev_priv->pc8.regsave.gtier = I915_READ(GTIER);
 	dev_priv->pc8.regsave.gen6_pmimr = I915_READ(GEN6_PMIMR);
 
-	ironlake_disable_display_irq(dev_priv, ~DE_PCH_EVENT_IVB);
-	ibx_disable_display_interrupt(dev_priv, ~SDE_HOTPLUG_MASK_CPT);
+	ironlake_disable_display_irq(dev_priv, 0xffffffff);
+	ibx_disable_display_interrupt(dev_priv, 0xffffffff);
 	ilk_disable_gt_irq(dev_priv, 0xffffffff);
 	snb_disable_pm_irq(dev_priv, 0xffffffff);
 
@@ -3915,34 +3915,26 @@ void hsw_pc8_restore_interrupts(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	unsigned long irqflags;
-	uint32_t val, expected;
+	uint32_t val;
 
 	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
 
 	val = I915_READ(DEIMR);
-	expected = ~DE_PCH_EVENT_IVB;
-	WARN(val != expected, "DEIMR is 0x%08x, not 0x%08x\n", val, expected);
+	WARN(val != 0xffffffff, "DEIMR is 0x%08x\n", val);
 
-	val = I915_READ(SDEIMR) & ~SDE_HOTPLUG_MASK_CPT;
-	expected = ~SDE_HOTPLUG_MASK_CPT;
-	WARN(val != expected, "SDEIMR non-HPD bits are 0x%08x, not 0x%08x\n",
-	     val, expected);
+	val = I915_READ(SDEIMR);
+	WARN(val != 0xffffffff, "SDEIMR is 0x%08x\n", val);
 
 	val = I915_READ(GTIMR);
-	expected = 0xffffffff;
-	WARN(val != expected, "GTIMR is 0x%08x, not 0x%08x\n", val, expected);
+	WARN(val != 0xffffffff, "GTIMR is 0x%08x\n", val);
 
 	val = I915_READ(GEN6_PMIMR);
-	expected = 0xffffffff;
-	WARN(val != expected, "GEN6_PMIMR is 0x%08x, not 0x%08x\n", val,
-	     expected);
+	WARN(val != 0xffffffff, "GEN6_PMIMR is 0x%08x\n", val);
 
 	dev_priv->pc8.irqs_disabled = false;
 
 	ironlake_enable_display_irq(dev_priv, ~dev_priv->pc8.regsave.deimr);
-	ibx_enable_display_interrupt(dev_priv,
-				     ~dev_priv->pc8.regsave.sdeimr &
-				     ~SDE_HOTPLUG_MASK_CPT);
+	ibx_enable_display_interrupt(dev_priv, ~dev_priv->pc8.regsave.sdeimr);
 	ilk_enable_gt_irq(dev_priv, ~dev_priv->pc8.regsave.gtimr);
 	snb_enable_pm_irq(dev_priv, ~dev_priv->pc8.regsave.gen6_pmimr);
 	I915_WRITE(GTIER, dev_priv->pc8.regsave.gtier);