Hello list and Ran, Well, the error I saw in dmesg about an unassignable address is something I had only seen one other time when a device was miswired. I flipped the USB-C connector over and it started working in USB3 ports, but at USB2 speeds. I thought of this days ago but figured the port should be handling it... On Windows the system reports a bad setup, so I think my SS descriptors are malformed. I'm using functionfs. I'll start a separate thread on this. On Linux the device connects as USB2 instead of reporting an error. If I use the NCM/ECM configfs driver debugging tools in Windows show me that the port is superspeed capable though registered as HS. Patches hit the list to fix this only a few days ago. Hooray! It seems I may be able to select device mode by writing to nodes in /sys/class/typec/port0. But I am still not sure. On Sun, Sep 20, 2020, at 8:20 PM, Ran Wang wrote: > 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"; > For anyone following along I did implement this. It may be necessary. I will see later. > 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). > It seems to work, the issue is that the hardware isn't handling the reversible connector properly. Cheers.
