62KB limit on modular SGDMA with PCIe

We have a working PCIe 4x link running on Arria II GX with a Win7 driver.

When we increase the size of the transfer in the descriptor beyond 62KB

the system hangs badly. I

s there some limit in the PCIe core or in the

modular SGDMA? Is there some problem with credits?

We have to process

an interrupt on the PC at the end of each descriptor, so this is slowing down

our data transfer rate.