I use Exar usb serial device on Jetson NX , running Jetpack 4.4 and 4.5.1
Kernel of 4.4 and 4.5.1 are 4.9-140 and 4.9-201
Running same EXAR usb serial driver
Linux 3.6.x and newer 1C
But EXAR usb uart seems only worked on Jetpack 4.4 , kernel 4.9-140
When it is running on Jetpack 4.5.1 , transmission are not worked properly.
I use a self-loop adaptor to test serial send and receive.
You can see log doesnt shows read_bulk_callback and submit_read_urb while running transmission on 4.5.1 , just open and close operation in driver message.
Is there any usb host modification in 4.9-201 affect this issue?
How can it be fixed ?