Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753035AbcD0MEa (ORCPT ); Wed, 27 Apr 2016 08:04:30 -0400 Received: from mail-lf0-f45.google.com ([209.85.215.45]:34139 "EHLO mail-lf0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751998AbcD0ME2 (ORCPT ); Wed, 27 Apr 2016 08:04:28 -0400 Subject: Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup To: changbin.du@intel.com, balbi@kernel.org References: <1461745745-3954-1-git-send-email-changbin.du@intel.com> Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Du@vger.kernel.org From: Sergei Shtylyov Message-ID: <488a2557-9a02-290c-f6e8-95f633c9a732@cogentembedded.com> Date: Wed, 27 Apr 2016 15:04:24 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <1461745745-3954-1-git-send-email-changbin.du@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1936 Lines: 61 Hello. On 4/27/2016 11:29 AM, changbin.du@intel.com wrote: > From: "Du, Changbin" > > The dwc3 controller can't generate a disconnect event after it is > stopped. Thus gadget dissconnect callback is not invoked when do > soft dissconnect. Call dissconnect here to workaround this issue. "Disconnect" everywhere. > Note, most time we still see disconnect be called that because > it is invoked by dwc3_gadget_reset_interrupt(). But if we > disconnect cable once pullup disabled quickly, issue can be > observed. > > Signed-off-by: Du, Changbin > --- > drivers/usb/dwc3/gadget.c | 33 ++++++++++++++++++++++++--------- > 1 file changed, 24 insertions(+), 9 deletions(-) > > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c > index 8e4a1b1..cd73187 100644 > --- a/drivers/usb/dwc3/gadget.c > +++ b/drivers/usb/dwc3/gadget.c [...] > @@ -1575,6 +1584,21 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) > is_on = !!is_on; > > spin_lock_irqsave(&dwc->lock, flags); > + /** > + * WORKAROUND: The dwc3 controller can't generate a disconnect > + * event after it is stopped. Thus gadget dissconnect callback > + * is not invoked when do soft dissconnect. Call dissconnect > + * here to workaround this issue. "Disconnect" everywhere. > + * Note, most time we still see disconnect be called that because I couldn't parse that. > + * it is invoked by dwc3_gadget_reset_interrupt(). But if we > + * disconnect cable once pullup disabled quickly, issue can be > + * observed. > + */ > + if (!is_on && (dwc->gadget.speed != USB_SPEED_UNKNOWN)) { > + dev_dbg(dwc->dev, "fake dissconnect event on pullup off\n"); Disconnect. > + dwc3_disconnect_gadget(dwc); > + dwc->gadget.speed = USB_SPEED_UNKNOWN; > + } > ret = dwc3_gadget_run_stop(dwc, is_on, false); > spin_unlock_irqrestore(&dwc->lock, flags); > [...] MBR, Sergei