MCSX_PEX_RX_SLAVE_PEX_CONFIGURATION
val = mcs_reg_read(mcs, MCSX_PEX_RX_SLAVE_PEX_CONFIGURATION);
mcs_reg_write(mcs, MCSX_PEX_RX_SLAVE_PEX_CONFIGURATION, val);
if (mcs_reg_read(mcs, MCSX_PEX_RX_SLAVE_PEX_CONFIGURATION) & BIT_ULL(req->port_id))
cfg = mcs_reg_read(mcs, MCSX_PEX_RX_SLAVE_PEX_CONFIGURATION);
mcs_reg_write(mcs, MCSX_PEX_RX_SLAVE_PEX_CONFIGURATION, cfg);