On Tue, May 12, 2020 at 09:25:38PM +0200, Claus Stovgaard wrote: > Hi all > > I have a system, using a Xilinx ZynqMP with kernel 4.19, using the > build in dwc3 core as a USB device. (It is a custom device using > ConfigFS / FunctionFS). > > In a certain scenario I would like to force the dwc3 to only connect > via superspeed and not fall back to USB2. > > What options exist for forcing the dwc3 to keep retry? The USB-3 spec forbids devices from operating only at SuperSpeed. Devices must be able to connect at high speed, although possibly with reduced functionality. Alan Stern > I know about the U2RSTECN from GCTL - > https://www.xilinx.com/html_docs/registers/ug1087/usb3_xhci___gctl.html > > So was wondering if other options existed, where I can force it to > continue try to connect as SuperSpeed. > > Or if it is possible to setup the high speed descriptors for ffs, so > the host automatically will reset the bus / device so it newer will be > reported as connected, unless it is with super speed.
