The system has TMS320C6678 as PCIE RC, the EP is implemented in FPGA device. Was able to bring up the link successfully after power up(using Code composer). After reset the FPGA(DSP does not got reset in this case), the PCIE link will go down. I have try the following to try the link back up:
1) write to link status control register bit 5 to enable retraining, the link seem to stay down
2).run the same PCIE init sequence, PCIE_InitPcieRc as boot code to init both RC and EP, the link seems to come up, but failed to do any configuration cycle.
My suspicion is that need to shut down the PCIe link in the DSP gracefully before asserting reset to the EP.
What is the correct sequence to bring the PCIE link back to operation after resetting the EP device?.
Thanks