Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756869AbcJTGAs (ORCPT ); Thu, 20 Oct 2016 02:00:48 -0400 Received: from mail-pf0-f179.google.com ([209.85.192.179]:36048 "EHLO mail-pf0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754335AbcJTGAq (ORCPT ); Thu, 20 Oct 2016 02:00:46 -0400 From: John Stultz To: lkml Cc: John Stultz , Wei Xu , Guodong Xu , Chen Yu , Amit Pundir , Rob Herring , Mark Rutland , John Youn , Douglas Anderson , Greg Kroah-Hartman , linux-usb@vger.kernel.org Subject: [RFC][PATCH] usb: dwc2: Make sure we disconnect the gadget state on reset Date: Wed, 19 Oct 2016 23:00:41 -0700 Message-Id: <1476943241-31810-1-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1875 Lines: 50 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)) -- 2.7.4