On Tue, 19 Nov 2024 20:18:00 +0100 Andrew Lunn <andrew@xxxxxxx> wrote: > > I think there is some confusion here. I will try to summarize: > > - Ihe iommu is supported by the Tegra SOC. > > - The way the mgbe driver is written the iommu DT property is REQUIRED. > > If it is required, please also include a patch to > nvidia,tegra234-mgbe.yaml and make iommus required. > I will add this when I submit a v2 of the patch. > > - "iommus" is a SOC DT property and is defined in tegra234.dtsi. > > - The mgbe device tree nodes in tegra234.dtsi DO have the iommus property. > > - There are no device tree changes required to to make this patch work. > > - This patch works fine with existing device trees. > > > > I will add the fallback however in case there is changes made to the iommu > > subsystem in the future. > > I would suggest you make iommus a required property and run the tests > over the existing .dts files. > > I looked at the history of tegra234.dtsi. The ethernet nodes were > added in: > > 610cdf3186bc604961bf04851e300deefd318038 > Author: Thierry Reding <treding@xxxxxxxxxx> > Date: Thu Jul 7 09:48:15 2022 +0200 > > arm64: tegra: Add MGBE nodes on Tegra234 > > and the iommus property is present. So the requires is safe. > > Please expand the commit message. It is clear from all the questions > and backwards and forwards, it does not provide enough details. > I will add more details when I submit V2. > I just have one open issue. The code has been like this for over 2 > years. Why has it only now started crashing? > It is rare for Nvidia Jetson users to use the mainline kernel. Nvidia provides a custom kernel package with many out of tree drivers including a driver for the mgbe controllers. Also, while the Orin AGX SOC (tegra234) has 4 instances of the mgbe controller, the Nvidia Orin AGX devkit only uses mgbe0. Connect Tech has carrier boards that use 2 or more of the mgbe controllers which is why we found the bug. Thanks, Parker
