Currently, two USB ports are operating with USB 3.0 (SuperSpeed). (TX2)
Is there any way to change to USB 2.0 (HighSpeed) by modifying the kernel source?
(Limitations:
Hardware change is not possible (e.g. insert a USB 2.0 hub))
Modifying the runtime by using the Shell does not matter,
but it must be permanently applied after rebooting.
I would have to ask first what your purpose is? Is there a use case?
FYI, any device which is not capable of USB3 would cause the port to self-slow to USB2 (or whatever speed the device is capable of). A USB2 HUB is just one example of this.
I suppose a device tree change would do this (someone from NVIDIA would have to comment, but basically this picks the arguments passed to the driver and picks the driver), but unless there is something unusual going on, whatever you are doing sounds like it might be doing it the hard way. Knowing more about what you want to accomplish could help.
Also, don’t forget to mention which release you are using, and if this is a developer kit carrier board.
It is simply a comparison test of USB3 and USB2 connectivity stability.
We had a problem of being disconnected occasionally when using an intel 3d camera connected to TX2.
I tried several methods, but since it is not 100% solved, I would like to use the method that I want to lower to USB2.
The problem is that we have to assemble and there is no space for the USB2 hub.
Therefore, I tried to check if there is no way to lower it to USB2 using only software.
I tested by changing the dts value as instructed. (disabled)
However, it has not changed to USB 2.0.
I am using the r28 version.
I modified “kernel-dts/quill-platforms/tegra186-quill-kernel-4.9.dtsi” and “kernel-dts/tegra186-quill-p3310-1000-a00-00-base.dts”, is that correct?
nvidia@tegra-ubuntu:~$ lsusb -t
/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci-tegra/3p, 5000M
|__ Port 2: Dev 2, If 0, Class=Mass Storage, Driver=usb-storage, 5000M <— …??
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci-tegra/4p, 480M