PCIe Root Complex DMA Test

Hello,

I enabled DMA testing for PCIe RP by following the topic below
https://forums.developer.nvidia.com/t/what-is-the-actual-maximum-speed-of-jetson-agx-xavier-pcie-ethernet/212429/8 and I have some questions below:

The Jetpack version is v5.1(Jetson Linux v35.2.1)

1. 
   

   The default of data size for DMA test is 255MB(BAR0_SIZE - 1MB), and when I try to change the BAR0_SIZE to 1GB to do a larger data size for DMA testing, it fails. The largest BAR0_SIZE I’ve tried to do DMA test successfully is 512MB. Is there any way I can start DMA testing if the data size is greater than 1GB?

   
   


2. 
   

   How can I change the max payload size of PCIe?

   
   


3. 
   

   Does Jetson AGX Xavier can support the max payload size over 256 bytes?

   
   

BR,

Hermes Wu