ikwzm / udmabuf

User space mappable dma buffer device driver for Linux.
BSD 2-Clause "Simplified" License
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RX BUFFER zero padded only on cold start #41

Closed noelpedro closed 1 year ago

noelpedro commented 4 years ago

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,

ikwzm commented 4 years ago

Thank you for the issue.

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