drm/i915/chv: Freq(opcode) request for CHV.

On CHV, All the freq request should be even. So, we need to make sure we
request the opcode accordingly.

v2: Avoid vairable for freq request (ville)
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -1252,8 +1252,10 @@ static void gen6_pm_rps_work(struct work_struct *work)
 	if (pm_iir & GEN6_PM_RP_UP_THRESHOLD) {
 		if (adj > 0)
 			adj *= 2;
-		else
-			adj = 1;
+		else {
+			/* CHV needs even encode values */
+			adj = IS_CHERRYVIEW(dev_priv->dev) ? 2 : 1;
+		}
 		new_delay = dev_priv->rps.cur_freq + adj;
 
 		/*
@@ -1271,8 +1273,10 @@ static void gen6_pm_rps_work(struct work_struct *work)
 	} else if (pm_iir & GEN6_PM_RP_DOWN_THRESHOLD) {
 		if (adj < 0)
 			adj *= 2;
-		else
-			adj = -1;
+		else {
+			/* CHV needs even encode values */
+			adj = IS_CHERRYVIEW(dev_priv->dev) ? -2 : -1;
+		}
 		new_delay = dev_priv->rps.cur_freq + adj;
 	} else { /* unknown event */
 		new_delay = dev_priv->rps.cur_freq;