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 <[e-mail]>
Signed-off-by: Chris Wilson <[e-mail]>
Reviewed-by: Keith Packard <[e-mail]>

drivers/gpu/drm/i915/i915_debugfs.c

···
 		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 &
···
 
 		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

···
 		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 */