Hello, we currently have a Jetson NX which is having degraded serial port performance after flashing L4T 35.1 using Jetpack 5.0.2.
On this NX, a sensor is connected to one of the serial ports (ttyTHS1, serial@3100000) at baudrate 460800. We are able to read this sensor with an excellent reliability on L4T 32.7.2 (each packet provided by the sensor contains a crc, and we had ~1 crc error every two hours or so.)
Now, after a fresh stock flash to L4T 35.1, the serial driver did not accept this baud rate because of rate tolerance issues (so a dmesg message said), so we had to change the device tree by changing the following line on the serial port block:
nvidia,adjust-baud-rates = <0 1000000 100>;
This permitted the baudrate 460800 to be accepted by the driver, however we now have several crc errors per second.
We are using the same reading code, same wiring and hardware.
There is error related to the serial port in dmesg.
We tried to change the final “100” tolerance value in the device tree (we tried 60, 100, 150, 200, 250) , without any noticeable impact on crc errors.
We tried different baudrates (921600, 230400), to no avail.
We reverted the device tree change above, those alternative baudrates were accepted by the driver, but no performance improvement.
Is there someting we can do to investigate further? I tried looking into the driver differences between those two L4T versions but many changes were made.
Thanks a lot for your help!