DMA to PCIe BARs on Jetson Orin

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
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Hi!

According to DMA to PCIe BARs, the stuff told that it is not allowed to use DMA on PCIe BAR region on Xavier NX.

I want to confirm if there are some upgrading kernel facilities for performing DMA to/from PCIe BAR regions on Jetson AGX Orin?

I’m using the latest version JetPack 5.1.1.

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Let me check with intenal team to update with you. Thanks

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@kayccc it would be really helpful to get a clear answer on this question. We also have a PCIe endpoint device from which we’re trying to fetch data from using Orin’s GPDMA facility an dmaengine_prep_dma_memcpy() targeting the device’s BAR. On other host SoC’s, this appears to work, but on the Orin, either we’re having some inconsistency in setting up the IOMMU mappings or this is not supported by GPDMA.

It would be very beneficial to both Nvidia and the community at large to provide a succinct example of DMAing from a PCIe endpoint device’s BAR, whether with GPDMA or the separate DMA engine residing inside Orin’s PCIe root port.

Thank you,

Berend

1 Like
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Please check How to Carry out DMA transfer when sending data using PCIe from NVIDIA Root Port to a custom end point

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Thanks for the pointer to the other thread, @b-sathishkumar. I followed up there as well.

Berend

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