Hello NXP,
According to the document "AN13164 iMX8MP PCIe Bandwith Analysis", it have the Linux PCI test and test by DMA.
The document "IMX8MPRM- i.MX 8M Plus Applications Processor Reference Manual - Document Number: IMX8MPRM Rev. 1, 06/2021" also show the "Embedded DMA" feature.
Could I write/read PCIe data by DMA ?
Thanks.
Best Regards,
Wayne.
Yes, you can use DMA in PCIe
Hello NXP,
How could I use the PCIe DMA ?
Could you provide any reference code or document ?
Thanks.
Best Regards,
Wayne.
Hi Wayne,
The documentation is IMX8MPRM.pdf section 11.4.2.4 DMA Controller.
The reference code is here: https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/pci/controller/dwc/pci-imx6.c?h=im...
Look for the function "imx6_pcie_local_dma_start". That code seems to have been removed from the latest kernel release, but I was able to add it back in and it seems to work. But it doesn't seem to be part of the pci_endpoint_test, so I'm unable to recreate the bandwidth results from AN13164 since NXP didn't describe how to run the benchmark.