On 10/19/2016 11:00 PM, John Stultz wrote: > I had seen some odd behavior with HiKey's usb-gadget interface > that I finally seemed to have chased down. Basically every other > time I pluged in the OTG port, the gadget interface would > properly initialize. The other times, I'd get a big WARN_ON > in dwc2_hsotg_init_fifo() about the fifo_map not being clear. > > Ends up If we don't disconnect the gadget state on reset, the > fifo-map doesn't get cleared properly, which causes WARN_ON > messages and also results in the device not properly being > setup as a gadget every other time the OTG port is connected. > > So this patch adds a call to dwc2_hsotg_disconnect() in the > reset path so the state is properly cleared. > > With it, the gadget interface initializes properly on every > plug in. > > I don't know if this is actually the right fix, but it seems > to work well. Feedback would be greatly appreciated! > > Cc: Wei Xu <xuwei5@xxxxxxxxxxxxx> > Cc: Guodong Xu <guodong.xu@xxxxxxxxxx> > Cc: Chen Yu <chenyu56@xxxxxxxxxx> > Cc: Amit Pundir <amit.pundir@xxxxxxxxxx> > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: John Youn <johnyoun@xxxxxxxxxxxx> > Cc: Douglas Anderson <dianders@xxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: linux-usb@xxxxxxxxxxxxxxx > Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> > --- > drivers/usb/dwc2/gadget.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c > index 24fbebc..5505001 100644 > --- a/drivers/usb/dwc2/gadget.c > +++ b/drivers/usb/dwc2/gadget.c > @@ -2519,6 +2519,8 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg, > > /* Kill any ep0 requests as controller will be reinitialized */ > kill_all_requests(hsotg, hsotg->eps_out[0], -ECONNRESET); > + /* Make sure everything is disconnected */ > + dwc2_hsotg_disconnect(hsotg); > > if (!is_usb_reset) > if (dwc2_core_reset(hsotg)) > Seems fine with our testing. Acked-by: John Youn <johnyoun@xxxxxxxxxxxx> Regards, John -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
