JTAG TRST pull-down resistor disables certain JTAG adapters
When the resistor (R2) is mounted, Xilinx platform cable is unable to
initialize the JTAG chain. Microsemi FlashPro works fine.
This might constitute a problem when there are Xilinx devices in the
carrier-mezzanine JTAG chain.
Consider disconnecting FPGA TRST pin from the FMC connector, leaving it only connected to the JTAG pin header on the mezzanine. Such solution needs to be tested first to see if disconnecting TRST pin breaks the JTAG chain.