Hello! I’ve been having a weird problem with using the /dev/ttyTHS1 UART (&uarta on DeviceTree, pins 203, 205) on Jetson Orin Nano. When receiving small packets (~ 12 bytes) on any baud rate (tested between 115200 and 500000) everything works fine. However, when trying to receive bigger packets (~…

Hi therealmatiss, Are you using the devkit or custom board for Orin Nano? What’s the Jetpack version in use? [image] therealmatiss: What could be the options to get DMA working correctly? If you want to run UART in DMA mode, please refer to the following thread for the fix. Solved: UART/S…

First, be aware that one UART can have two drivers servicing it at the same time. One is the legacy driver, and this produces the “/dev/ttyS#” device special file; the other is the “/dev/ttyTHS#” name format, and the “THS” means “Tegra High Speed”, referring to the DMA you have mentioned. Legacy is …

I understand but the /dev/ttyS# device is not being used and it’s only using the /dev/ttyTHS - that is clearly not the issue. dmesg on boot does also verify that it has sucessfully brought up the specific /dev/ttyTHS1. I am pretty sure that this is Nvidia’s misconfiguration regarding the DMA in UAR…

NVIDIA would have to answer that. Clock rate issues though might still be an issue at higher speeds as TX and RX, though working together, are technically different UARTs. Have you tried testing in loopback modes? The Jetson clock itself is known to become an issue at the higher speeds which did not…

It’s Jetpack 6.2.2. The issue is replicable both on custom board and on DevKit. I tried your suggestion and it works after adding this to my overlay: fragment@6 { target = <&uarta>; __overlay__ { dmas = <&gpcdma 8>, <&gpcdma 8>; dma-names = "rx", "tx"; iommus = <&smmu_niso0 TEGRA2…

Yes, it will be fixed in the next official Jetpack release.

DMA on /dev/ttyTHS1 corrupts receiving data

Robotics & Edge Computing Jetson Systems Jetson Orin Nano

KevinFFF May 7, 2026, 2:32am 8

Hi therealmatiss,

Are you using the devkit or custom board for Orin Nano?
What’s the Jetpack version in use?

If you want to run UART in DMA mode, please refer to the following thread for the fix.
Solved: UART/Serial Port not working after upgradint to Jetpack 6.2.2 (Orin Nano/NX) - #7 by KevinFFF

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DMA on /dev/ttyTHS1 corrupts receiving data

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