Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755603AbcJYWOF (ORCPT ); Tue, 25 Oct 2016 18:14:05 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:47176 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753183AbcJYWOE (ORCPT ); Tue, 25 Oct 2016 18:14:04 -0400 Subject: Re: [RFC][PATCH] usb: dwc2: Make sure we disconnect the gadget state on reset To: John Stultz , John Youn References: <1476943241-31810-1-git-send-email-john.stultz@linaro.org> CC: lkml , Wei Xu , Guodong Xu , Chen Yu , "Amit Pundir" , Rob Herring , "Mark Rutland" , Douglas Anderson , Greg Kroah-Hartman , "linux-usb@vger.kernel.org" From: John Youn Message-ID: <5099a06b-b0b9-348d-4043-141d96c55bb7@synopsys.com> Date: Tue, 25 Oct 2016 15:14:01 -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: 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: 2654 Lines: 68 On 10/25/2016 2:56 PM, John Stultz wrote: > On Tue, Oct 25, 2016 at 2:29 PM, John Youn wrote: >> 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 > > Awesome! Thanks so much for the review and testing! > > I'm curious, did you happen to have any thoughts or objections on the > "dwc2: Force port resume on switching to device mode" patch > (https://patchwork.kernel.org/patch/9375965/ ) as well? Sorry, must have missed that one. We'll take a look. Regards, John