Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965988AbcJYVaH (ORCPT ); Tue, 25 Oct 2016 17:30:07 -0400 Received: from smtprelay.synopsys.com ([198.182.60.111]:50251 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933188AbcJYVaE (ORCPT ); Tue, 25 Oct 2016 17:30:04 -0400 Subject: Re: [RFC][PATCH] usb: dwc2: Make sure we disconnect the gadget state on reset To: John Stultz , lkml References: <1476943241-31810-1-git-send-email-john.stultz@linaro.org> CC: Wei Xu , Guodong Xu , Chen Yu , Amit Pundir , Rob Herring , Mark Rutland , John Youn , Douglas Anderson , "Greg Kroah-Hartman" , "linux-usb@vger.kernel.org" From: John Youn Message-ID: Date: Tue, 25 Oct 2016 14:29:31 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1476943241-31810-1-git-send-email-john.stultz@linaro.org> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.9.139.37] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2099 Lines: 59 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 > Cc: Guodong Xu > Cc: Chen Yu > Cc: Amit Pundir > Cc: Rob Herring > Cc: Mark Rutland > Cc: John Youn > Cc: Douglas Anderson > Cc: Greg Kroah-Hartman > Cc: linux-usb@vger.kernel.org > Signed-off-by: John Stultz > --- > 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 Regards, John