R0b0t1

I've some more observations. Checking the code in drivers/usb/dwc3/core.c I was unable to find what actually allows you to select the mode if specifying OTG. I have devices in /sys/class/udc and they function properly via configfs when plugged into a USB2 only port. If I plug them into a superspeed port I get nothing in dmesg on the host side. At first, I did get a response on the host, in the form of: [591550.770819] usb 1-1.2: new full-speed USB device number 76 using xhci_hcd [591550.870962] usb 1-1.2: device descriptor read/64, error -32 [591551.078865] usb 1-1.2: device descriptor read/64, error -32 [591551.286875] usb 1-1.2: new full-speed USB device number 77 using xhci_hcd [591551.386873] usb 1-1.2: device descriptor read/64, error -32 [591551.594859] usb 1-1.2: device descriptor read/64, error -32 [591551.703160] usb 1-1-port2: attempt power cycle However now I get no driver activity when binding the UDC in configfs or loading or unloading the respective modules. Kernel is 5.7.15 w/ patches. It doesn't seem like bad USB-C wiring fried port or tripped a polyfuse, the port still works after attempting USB3 device mode.

I made progress. The default device tree sets the first dwc3 controller as "otg." Unfortunately this seems to not have much effect. I've tried looking for a software switch and also tried plugging the board in as a device. How do you set this without needing a reboot? Changing the two DWC3 nodes in the file "arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi:" &usbdrd3_0 { status = "okay"; }; &usbdrd_dwc3_0 { status = "okay"; dr_mode = "peripheral"; }; &usbdrd3_1 { status = "okay"; }; &usbdrd_dwc3_1 { status = "okay"; dr_mode = "peripheral"; }; They are both listed in /sys/class/udc: # ls /sys/class/udc fe800000.usb fe900000.usb But, again, I'd like to change mode without needing to reboot. I'm also unsure how compatible the Type-C port is.

Hello, using the image provided at https://www.armbian.com/rockpro64/ the board works when booted via uSD card but not via MMC. There appears to be no device mode USB drivers installed. I pulled the kernel sources with `armbian-config` and compiled them myself making sure to select dual-mode support for the DWC2 and DWC3 drivers. The kernel boots after install, but I still see nothing in /sys/class/udc and am unable to see any dwc2/3 drivers (save dwc2_pci and some dwc3 i3c drivers). I'm able to load libcomposite, the configfs driver, but that does not pull in a USB device mode driver. I'm unable to attach armbian monitor status right now but will update my post with it.