Hi Sid, > -----Original Message----- > From: Sid Spry <sid@xxxxxxx> > Sent: Saturday, September 19, 2020 1:59 PM > To: Ran Wang <ran.wang_1@xxxxxxx> > Cc: linux-usb@xxxxxxxxxxxxxxx > Subject: Re: Enabling Device DWC3 Device Mode > > Hello list and Ran, I've some more observations. Firstly, I have to set the dwc3 > mode to peripheral directly. Checking the code I was unable to find what > actually allows you to select the mode if specifying OTG. Yeah, I also think debugging on peripheral firstly would be easier than 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: So the gadget registration for DWC3 UDC encountered no error, right? dwc3_core_init_mode()->dwc3_gadget_init()->usb_add_gadget_udc() return 0? If yes, it looks like SoC internal configuring has no big issue, I think. > [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 For the speed issue (expect SS but got FS), you could try adding below property to dwc3 node, On our platform this is necessary (see dwc3_gadget_set_speed()): maximum-speed = "super-speed"; If the get descriptor read issue still happen with above change, maybe you need to check PHY status, or using protocol-analyzer to see what happen on bus. > 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 a fried the port or tripped a polyfuse, the port still works > after attempting USB3 device mode. How about dr_mode="host"? Does it work? I think it would help to verify your HW is good to go (such as PHY at least). Regards, Ran
