TTY device reconnection issue on the Jetson AGX Orin

[soonhong.jung]

Hello,

I have a reconnection issue with a ublox GPS.
Once connected, everything works fine. However, once you disconnect and try to reconnect, no more data comes in.

Given that the same phenomenon occurs in all seven Orins we own, I don’t think it’s a particular orin board problem.
Jetpack SDK version is 5.1.1.

Simple test is possible in the following ways.

1. connect ublox device to Orin by usb port ( $ cat /dev/ttyACM0 )
2. disconnect ( Ctrl + c )
3. reconnect ( $ cat /dev/ttyACM0 )

You can verify that the device is no longer functioning by performing the above tests.

Although it looks similar to the Topic 239866, we have not yet found a solution except for physical methods (reboot Orin, reconnect usb cable…).

Thanks.

[JerryChang]

hello soonhong.jung,

is there any failure messages for reference?
please setup a terminal for running $ dmesg --follow, and please also gather the kernel logs again.

[soonhong.jung]

When I ran $ dmesg --follow, there is no error message.
However, as guided by Topic 256804,
Applying the usb patch (Jetson/L4T/r35.3.x patches - eLinux.org), will resolve it.
I hope this patch will be applied to the next version of Jetpack.
Thank you.