Hi Sergei, On Thursday, June 06, 2019 16:17 Sergei Shtylyov wrote: > > Hello! > > On 06.06.2019 5:54, Ran Wang wrote: > > > When DWC3 is set to host mode by programming register DWC3_GCTL, VBUS > > (or its control signal) will turn on immediately on related Root Hub > > ports. Then the VBUS will be de-asserted for a little while during > > xhci reset (conducted by xhci driver) for a little while and back to normal. > > > > This VBUS glitch might cause some USB devices emuration fail if kernel > > Enumeration. :-)
Thanks, will correct it in next version Regards, Ran > > boot with them connected. One SW workaround which can fix this is to > > program all PORTSC[PP] to 0 to turn off VBUS immediately after setting > > host mode in DWC3 driver(per signal measurement result, it will be too > > late to do it in xhci-plat.c or xhci.c). > > > > Signed-off-by: Ran Wang <ran.wan...@nxp.com> > > Reviewed-by: Rob Herring <r...@kernel.org> > [...] > > MBR, Sergei
