IGC_RCTL_SBP
reg_rctl &= ~(IGC_RCTL_SBP | IGC_RCTL_UPE);
reg_rctl |= IGC_RCTL_SBP;
reg_rctl |= IGC_RCTL_SBP;
rctl &= ~IGC_RCTL_SBP;
temp_rctl = rctl & ~(IGC_RCTL_EN | IGC_RCTL_SBP);