I am running TX1 24.2.1 as a PCIe root with Zynq endpoint. Zynq uses VDMA to stream video to TX1.
It works OK most of the time, but sometimes after many minutes (sometimes hours) PCIe stalls.
I compared TX1 register values and see only 2 differences between normal operation and stall:
AFI_CONFIGURATION_0 bit INITIATOR_WRITE_IDLE
sudo busybox devmem 0x010038AC w
0x00FE8E41 - before stall
0x00FC8E41 - after stall
AFI_REQ_PENDING_0 bits TMS0C02SM_NONISO_PENDING and TMS0C02SM_COH_REQUEST_PEND
sudo busybox devmem 0x010038F4 w
0x00000000 - before stall
0x00000009 - after stall
Could you, please, explain what this “request pending” means, what could have caused it and what can be my next steps to troubleshoot the problem.