drm/i915: Update ring freq for full gpu freq range

In __gen6_update_ring_freq, use the full range of
possible gpu frequencies from max_freq to min_freq.
The actual gpu frequency could be outside the range
from max_freq_softlimit to min_freq_softlimit due
to power/thermal constraints.
Signed-off-by: Tom O'Rourke <Tom.O'Rourke@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4915,9 +4915,9 @@ static void __gen6_update_ring_freq(struct drm_device *dev)
 	 * to use for memory access.  We do this by specifying the IA frequency
 	 * the PCU should use as a reference to determine the ring frequency.
 	 */
-	for (gpu_freq = dev_priv->rps.max_freq_softlimit; gpu_freq >= dev_priv->rps.min_freq_softlimit;
+	for (gpu_freq = dev_priv->rps.max_freq; gpu_freq >= dev_priv->rps.min_freq;
 	     gpu_freq--) {
-		int diff = dev_priv->rps.max_freq_softlimit - gpu_freq;
+		int diff = dev_priv->rps.max_freq - gpu_freq;
 		unsigned int ia_freq = 0, ring_freq = 0;
 
 		if (INTEL_INFO(dev)->gen >= 8) {