RBCPR_CTL_UP_THRESHOLD_SHIFT
reg_mask <<= RBCPR_CTL_UP_THRESHOLD_SHIFT;
reg_mask <<= RBCPR_CTL_UP_THRESHOLD_SHIFT;
val <<= RBCPR_CTL_UP_THRESHOLD_SHIFT;
val = desc->up_threshold << RBCPR_CTL_UP_THRESHOLD_SHIFT;