Even with the rps debug messages signficantly recuced  by
 commit 
67956867aa07c59d6d83628bbc9ee4bd9799a1e1
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Tue Sep 2 15:12:17 2014 +0300
    drm/i915: Don't spam dmesg with rps messages on vlv/chv
we still get an inordinate amount of spam from this. Just kill the debug
print. If someone wants to observe it they can just use the tracepoint.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
 
                      "Odd GPU freq value\n"))
                val &= ~1;
 
-       if (val != dev_priv->rps.cur_freq) {
-               DRM_DEBUG_DRIVER("GPU freq request from %d MHz (%u) to %d MHz (%u)\n",
-                                vlv_gpu_freq(dev_priv, dev_priv->rps.cur_freq),
-                                dev_priv->rps.cur_freq,
-                                vlv_gpu_freq(dev_priv, val), val);
-
+       if (val != dev_priv->rps.cur_freq)
                vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
-       }
 
        I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, val));