PCIE Driver R32.2 - Is 64bit DMA patch required?

Board TX2
L4T 32.2.1
Kernel 4.9.140-tegra

Hi,

I’m trying to port a PCI driver which works on L4T 28.2.1 to L4T 32.2.1.

In the L4T 28.2.1 version, there was a patch required, to set the DMA buffer addressing to 64bit (I think) as detailed in

https://devtalk.nvidia.com/default/topic/1002486/jetson-tx2/iommu-unhandled-context-fault-on-pci-device-dma/

Is something similar required for L4T32.2.1? I noticed that there is now a pci-tegra-dw driver. Should I enable this instead? Is there documentation I can refer too?

Apologies for the vague question but I am new to PCIE drivers and am inheriting someone else’s code.

Any help appreciated.

Thanks.

Hi,

pci-tegra-dw driver is for Jetson AGX.
Jetson TX2 PCIe is supported by pci-tegra driver in L4T 32.2.1.
L4T 32.2.1 has MSI addr size fix. L4T 28.2.1 MSI addr might still fail in some corner cases.
So, I don’t recommend porting pci-tegra from L4T 28.2.1 to L4T 32.2.1.

Thanks,
Manikanta

Hi,
Thanks for your response.
I’m not actually porting pci-tegra from L4T 28.2.1 to L4T 32.2.1. I am trying to use our PCI device driver (of type pci_dev), which runs on L4T 28.2.1, on L4T 32.2.1.
For this driver to run on L4T 28.2.1 a patch was required to be applied to the pci-tegra module, as discussed in

https://devtalk.nvidia.com/default/topic/1002486/jetson-tx2/iommu-unhandled-context-fault-on-pci-device-dma/

I would liked to know if this same patch is required to pci-tegra L4T 32.2.1.

Sorry for the misunderstanding.

Thanks

Hi,

If you are referring to patch uploaded at below location, then it is not required.
https://devtalk.nvidia.com/default/topic/1002486/jetson-tx2/iommu-unhandled-context-fault-on-pci-device-dma/post/5127145/#5127145

Thanks,
Manikanta