I use xdma base on K7 fpga as endpoint. It can transfer data to pc base on ububtu operation system. And I write a simple linux drive to do this.
I use msi interrupt and enable two user interrupt. The driver can handle all of interrupt from xdma.But I find a strange problem. Pc always receive once interrupt that driver never enabled every transfer operation.I try to read interrupt request register and the value always zero. Why xdma can transmission a interrupt witt "IRQ Block User Interrupt Request" and "IRQ Block Channel Interrupt Request" value equal zero?