drm/i915: Unify the appearance of gen3/4 irq_postistall hooks

Do the irq_mask/enable_mask setup in the same way on gen3/4, and also
reorder the steps to make the code more uniform.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170818183705.27850-9-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/i915_irq.c

@@ -3769,8 +3769,6 @@ static int i915_irq_postinstall(struct drm_device *dev)
 
 	GEN3_IRQ_INIT(, dev_priv->irq_mask, enable_mask);
 
-	i915_enable_asle_pipestat(dev_priv);
-
 	/* Interrupt setup is already guaranteed to be single-threaded, this is
 	 * just to make the assert_spin_locked check happy. */
 	spin_lock_irq(&dev_priv->irq_lock);
@@ -3778,6 +3776,8 @@ static int i915_irq_postinstall(struct drm_device *dev)
 	i915_enable_pipestat(dev_priv, PIPE_B, PIPE_CRC_DONE_INTERRUPT_STATUS);
 	spin_unlock_irq(&dev_priv->irq_lock);
 
+	i915_enable_asle_pipestat(dev_priv);
+
 	return 0;
 }
 
@@ -3935,18 +3935,26 @@ static int i965_irq_postinstall(struct drm_device *dev)
 	I915_WRITE(EMR, error_mask);
 
 	/* Unmask the interrupts that we always want on. */
-	dev_priv->irq_mask = ~(I915_ASLE_INTERRUPT |
-			       I915_DISPLAY_PORT_INTERRUPT |
-			       I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
-			       I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
-			       I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
+	dev_priv->irq_mask =
+		~(I915_ASLE_INTERRUPT |
+		  I915_DISPLAY_PORT_INTERRUPT |
+		  I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
+		  I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
+		  I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
 
-	enable_mask = ~dev_priv->irq_mask;
-	enable_mask |= I915_USER_INTERRUPT;
+	enable_mask =
+		I915_ASLE_INTERRUPT |
+		I915_DISPLAY_PORT_INTERRUPT |
+		I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
+		I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
+		I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT |
+		I915_USER_INTERRUPT;
 
 	if (IS_G4X(dev_priv))
 		enable_mask |= I915_BSD_USER_INTERRUPT;
 
+	GEN3_IRQ_INIT(, dev_priv->irq_mask, enable_mask);
+
 	/* Interrupt setup is already guaranteed to be single-threaded, this is
 	 * just to make the assert_spin_locked check happy. */
 	spin_lock_irq(&dev_priv->irq_lock);
@@ -3955,8 +3963,6 @@ static int i965_irq_postinstall(struct drm_device *dev)
 	i915_enable_pipestat(dev_priv, PIPE_B, PIPE_CRC_DONE_INTERRUPT_STATUS);
 	spin_unlock_irq(&dev_priv->irq_lock);
 
-	GEN3_IRQ_INIT(, dev_priv->irq_mask, enable_mask);
-
 	i915_enable_asle_pipestat(dev_priv);
 
 	return 0;