RX BUFFER zero padded only on cold start

[noelpedro]

Hi all,

My design is a simple loopback axi_dma mm2s to axi_dma s2mm. On a xilinx zynqMP ultrascale+ zcu102.

I was wondering why only on a cold start (first run of userspace app is the RX buffer all zero)?
All sequential runs the RX buffer equals the TX buffer.

I tried a FIFO in btween the transaction, but got the same result.

thanks,

[KAWAZOME Ichiro]

Thank you for the issue.

Is this issue related to udmabuf?
There is too little information and I can't answer anything.