diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index cc3c2d9eb7f40dc9825d26e096cab82cf073b6ec..c198dbad3e8286f5b202228206891f4ef58d995e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -755,12 +755,15 @@ static bool vlv_compute_drain_latency(struct drm_crtc *crtc,
 		return false;
 
 	entries = DIV_ROUND_UP(clock, 1000) * pixel_size;
-	if (IS_CHERRYVIEW(dev))
-		*prec_mult = (entries > 32) ? 16 : 8;
-	else
-		*prec_mult = (entries > 128) ? 64 : 32;
+
+	*prec_mult = IS_CHERRYVIEW(dev) ? 16 : 64;
 	*drain_latency = (64 * (*prec_mult) * 4) / entries;
 
+	if (*drain_latency > DRAIN_LATENCY_MASK) {
+		*prec_mult /= 2;
+		*drain_latency = (64 * (*prec_mult) * 4) / entries;
+	}
+
 	if (*drain_latency > DRAIN_LATENCY_MASK)
 		*drain_latency = DRAIN_LATENCY_MASK;