drm/i915/vlv: fixup DDR freq detection per Punit spec

Either the docs were wrong or the values have changed since the old days
before we had wheels.

Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 13afd54ca6e9..a5778e59cc15 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5319,15 +5319,22 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
         mutex_unlock(&dev_priv->rps.hw_lock);
         switch ((val >> 6) & 3) {
         case 0:
-        case 1:
                 dev_priv->mem_freq = 800;
                 break;
-        case 2:
+        case 1:
                 dev_priv->mem_freq = 1066;
                 break;
-        case 3:
+        case 2:
                 dev_priv->mem_freq = 1333;
                 break;
+        case 3:
+                /*
+                 * Probably a BIOS/Punit bug, or a new platform we don't
+                 * support yet.
+                 */
+                WARN(1, "invalid DDR freq detected, assuming 800MHz\n");
+                dev_priv->mem_freq = 800;
+                break;
         }
         DRM_DEBUG_DRIVER("DDR speed: %d MHz", dev_priv->mem_freq);