As mentioned in earlier post, I have developed a custom carrier for the Nano. After struggling for a long time with the wrong Nano module (A02 instead of B01), I found that my board was working OK. The ethernet, CSI, USB3.0, I2C and USB2.0 devices all enumerated and seemed to be working.
The USB2.0 interface (on the Jetson’s USB2) is used to connected a high-speed USB enabled microcontroller which acts as a CDC device. While developing the firmware for this microcontroller something odd has come up. The CDC bulk transfers time-out when using the interface. However when a WiFi USB stick is inserted in the USB 3.0 Type A connector on the carrier is inserted, the CDC bulk transfers come through as expected. When trying different USB devices (a Gigabit Ethernet dongle, USB thumb drive, wireless keyboard receiver, …) the transfers time-out. When I try to do the transfers in a loop for a number of times, the interface gives time-outs until I plug in a WiFi stick.
This perplexed me and encouraged me to review my board design, but after checking everything I could think of I believe it is a software issue. The only clue I am trying to investigate is that powertop shows a kWork process called
tegra_xusb_boost_cpu_freq_fn when the USB WiFi stick is plugged in and does not show up otherwise.
Is there anyone who might have encountered this kind of issue with USB devices or knows how I could make sure the CDC bulk transfers come through properly without having to plug in a WiFi stick. Is there a way I can enable the
Thanks in advance!