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>

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 13afd54..a5778e5 100644 (file)
--- 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);