DMA is not working in linked list mode

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

Hi,
I’m trying to communicate between two jetson xavier board through pcie interface, where one one jetson xavier acts as RC and another as End point.

When i initiate the transfer with write file in debugfs interface, it is working. I verified the destination location through devmem utility and found it is filled with some random values after successfull transfer

But when i initiate the transfer with write_ll file in debugfs interface, though the result printed as DMA-WRITE-LL PASSED but the value present in destination address + 64k was not changed.

3

There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.
Thanks

How are you using ‘devmem’ tool here? because input to devmem tool should always be physical address whereas the DMA address here is an IOVA address (as PCIe has SMMU enabled) and not the direct physical address.
Also, can you give me the full path of the write/write_ll debugfs entries?