MTW_PHY_SHPRE
switch ((phy & MTW_PHY_MCS) & ~MTW_PHY_SHPRE) {
if (phy & MTW_PHY_SHPRE)
if (le16toh(txwi->phy) & MTW_PHY_SHPRE)
mcs |= MTW_PHY_SHPRE;