Signal reflection on SPI

[aminpix]

We have designed a board in which the MOSI signal of the microcontroller is connected to the SI pin of a flash, xilinx FPGA and a JTAG connector. Micro-controller supervise and control the FPGA programming. We use the JTAG connector for initial programming of the flash and after that the connector is useless.

The problem we have is signal reflection on the unused trace, connected to the JTAG. All three chips are very close, but JTAG connector is almost 15" away from them. When we cut the JTAG trace, and make the stub shorter, the problem will be solved. Is there any solution for unused long traces like our circuit?
If I put a series resistor on the trace (before JTAG connector) can I solve the reflection issue?

 

[FvM]

Not possible to remove the problem completely.

I guess the reflection can be tolerated as long as no double clock edges or overshoot beyond maximum ratings are brought up. Series resistors at the line branch (30 - 60 ohms) might help. At worst case, a tristate driver for SCK that is only enabled during initial programming.