drm/i915: report correct render clock frequencies on SNB

Fix up the debug file to report the right frequencies.  On SNB, we program
the PCU with a frequency ratio, which is multiplied by 100MHz on the CPU
side.  But GFX only runs at half that, so report it as such to avoid
confusion.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -892,7 +892,7 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused)
 		seq_printf(m, "Render p-state limit: %d\n",
 			   rp_state_limits & 0xff);
 		seq_printf(m, "CAGF: %dMHz\n", ((rpstat & GEN6_CAGF_MASK) >>
-						GEN6_CAGF_SHIFT) * 100);
+						GEN6_CAGF_SHIFT) * 50);
 		seq_printf(m, "RP CUR UP EI: %dus\n", rpupei &
 			   GEN6_CURICONT_MASK);
 		seq_printf(m, "RP CUR UP: %dus\n", rpcurup &
@@ -908,15 +908,15 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused)
 
 		max_freq = (rp_state_cap & 0xff0000) >> 16;
 		seq_printf(m, "Lowest (RPN) frequency: %dMHz\n",
-			   max_freq * 100);
+			   max_freq * 50);
 
 		max_freq = (rp_state_cap & 0xff00) >> 8;
 		seq_printf(m, "Nominal (RP1) frequency: %dMHz\n",
-			   max_freq * 100);
+			   max_freq * 50);
 
 		max_freq = rp_state_cap & 0xff;
 		seq_printf(m, "Max non-overclocked (RP0) frequency: %dMHz\n",
-			   max_freq * 100);
+			   max_freq * 50);
 
 		__gen6_gt_force_wake_put(dev_priv);
 	} else {

drivers/gpu/drm/i915/intel_display.c

@@ -6930,7 +6930,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 		DRM_ERROR("timeout waiting for pcode mailbox to finish\n");
 	if (pcu_mbox & (1<<31)) { /* OC supported */
 		max_freq = pcu_mbox & 0xff;
-		DRM_DEBUG_DRIVER("overclocking supported, adjusting frequency max to %dMHz\n", pcu_mbox * 100);
+		DRM_DEBUG_DRIVER("overclocking supported, adjusting frequency max to %dMHz\n", pcu_mbox * 50);
 	}
 
 	/* In units of 100MHz */