drm/i915: Move gt/pm irq handling out from irq disabled section on VLV

No need to actually handle the GT/PM interrupt while we have interrupt
sources disabled. Move the actual processing to happen after we've
restored VLV_IER and master interrupt enable.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460571598-24452-11-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_irq.c

@@ -1819,11 +1819,6 @@ static irqreturn_t valleyview_irq_handler(int irq, void *arg)
 		if (pm_iir)
 			I915_WRITE(GEN6_PMIIR, pm_iir);
 
-		if (gt_iir)
-			snb_gt_irq_handler(dev, dev_priv, gt_iir);
-		if (pm_iir)
-			gen6_rps_irq_handler(dev_priv, pm_iir);
-
 		if (iir & I915_DISPLAY_PORT_INTERRUPT)
 			hotplug_status = i9xx_hpd_irq_ack(dev_priv);
 
@@ -1842,6 +1837,11 @@ static irqreturn_t valleyview_irq_handler(int irq, void *arg)
 		I915_WRITE(VLV_MASTER_IER, MASTER_INTERRUPT_ENABLE);
 		POSTING_READ(VLV_MASTER_IER);
 
+		if (gt_iir)
+			snb_gt_irq_handler(dev, dev_priv, gt_iir);
+		if (pm_iir)
+			gen6_rps_irq_handler(dev_priv, pm_iir);
+
 		if (hotplug_status)
 			i9xx_hpd_irq_handler(dev, hotplug_status);