On Mon, Oct 19, 2020 at 01:27:35PM +0200, Dmitry N. Mikushin wrote: > Dear All, > > I'm confused by the USB gadget mode on the recent Intel SoCs, such as > Gemini Lake. The /sys/class/udc is empty, and a SoC can't present > itself as a IoT gadget this way, yet definitely being designed as > such. I've noticed the concept of dual-role-device, which seems to > replace the OTG. Particularly, Harry Pan mentioned that Gemini Lake > supports DRD in port 0. So do you have the dwc3 (the USB device controller) PCI device available/visible on your system? What do you get if you run: lspci -nn|grep USB The DWC3 PCI device ID on Gemini lake is 0x31aa (search PCI_DEVICE_ID_INTEL_GLK in drivers/usb/dwc3/dwc3-pci.c). Which board/product are you using. Which kernel are you using? Is the dwc3 driver enabled in your kernel? Which gadget are you testing with? g_zero? thanks, -- heikki