Index: sys/dev/drm2/i915/intel_display.c
===================================================================
--- sys/dev/drm2/i915/intel_display.c	(revision 271102)
+++ sys/dev/drm2/i915/intel_display.c	(working copy)
@@ -735,7 +735,7 @@ void intel_wait_for_vblank(struct drm_device *dev,
 	/* Wait for vblank interrupt bit to set */
 	if (_intel_wait_for(dev,
 	    I915_READ(pipestat_reg) & PIPE_VBLANK_INTERRUPT_STATUS,
-	    50, 1, "915vbl"))
+	    50, !kdb_active, "915vbl"))
 		DRM_DEBUG_KMS("vblank wait timed out\n");
 }