Re: dwc3 gadget and USB3

["gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>]

On Wed, Mar 08, 2023 at 06:12:51PM +0000, Joakim Tjernlund wrote:
> On Wed, 2023-03-08 at 18:25 +0100, Greg KH wrote:
> > On Wed, Mar 08, 2023 at 05:10:17PM +0000, Joakim Tjernlund wrote:
> > > we are using fsl-ls1043a-rdb based design but with a ls1023a SOC and
> > > use USB0 in gadget mode running either NCM or RNDIS ethernet on top.
> > > 
> > > When we connect the gadget to a PC(Linux of Windows) over an USB2 hub,
> > > networking(NCM or RNDIS) works well.
> > > 
> > > However, when we connect the gadget directly to the PC/laptop which uses USB3
> > > we see something odd:
> > >   Ping from PC to gadget works.
> > >   Ping from gadget to laptop does not. However if we also ping from PC at the same time we
> > >   see gadget to PC start working.
> > > Seems like ping from the PC tiggers the gadget to see incoming pkgs somehow.
> > > 
> > > Any idea what might be wrong or how to debug this?
> > > Kernel 5.15.87
> > 
> > 5.15.y is very old, does this also happen on 6.2?
> > 
> 
> I just tried 6.1.15 and the problem remains, I hope that is close enough ?

It's good enough :)

Have any logs at all that show any problems?  Also, you might want to
 cc:  the dwc3 maintainer...

 thanks,

 greg k-hj