Minor cleanup.  Would be nice to use an enum for channel in the DPIO
macros so we don't mix up pipes and channels, but that's for another
patch.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
        unsigned long demph_reg_value, preemph_reg_value,
                uniqtranscale_reg_value;
        uint8_t train_set = intel_dp->train_set[0];
-       int port;
-
-       if (dport->port == PORT_B)
-               port = 0;
-       else if (dport->port == PORT_C)
-               port = 1;
-       else
-               BUG();
+       int port = vlv_dport_to_channel(dport);
 
        WARN_ON(!mutex_is_locked(&dev_priv->dpio_lock));