Re: Any example of USB gadget for DRD device mode on Intel Gemini Lake?

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

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