Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932172AbdDPIUC (ORCPT ); Sun, 16 Apr 2017 04:20:02 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56538 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755860AbdDPIDg (ORCPT ); Sun, 16 Apr 2017 04:03:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Janusz Dziedzic , Felipe Balbi Subject: [PATCH 4.4 03/18] usb: dwc3: gadget: delay unmap of bounced requests Date: Sun, 16 Apr 2017 10:02:26 +0200 Message-Id: <20170416080212.911894738@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170416080212.713469777@linuxfoundation.org> References: <20170416080212.713469777@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2143 Lines: 68 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Janusz Dziedzic commit de288e36fe33f7e06fa272bc8e2f85aa386d99aa upstream. In the case of bounced ep0 requests, we must delay DMA operation until after ->complete() otherwise we might overwrite contents of req->buf. This caused problems with RNDIS gadget. Signed-off-by: Janusz Dziedzic Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/gadget.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -235,6 +235,7 @@ void dwc3_gadget_giveback(struct dwc3_ep int status) { struct dwc3 *dwc = dep->dwc; + unsigned int unmap_after_complete = false; int i; if (req->queued) { @@ -259,11 +260,19 @@ void dwc3_gadget_giveback(struct dwc3_ep if (req->request.status == -EINPROGRESS) req->request.status = status; - if (dwc->ep0_bounced && dep->number <= 1) + /* + * NOTICE we don't want to unmap before calling ->complete() if we're + * dealing with a bounced ep0 request. If we unmap it here, we would end + * up overwritting the contents of req->buf and this could confuse the + * gadget driver. + */ + if (dwc->ep0_bounced && dep->number <= 1) { dwc->ep0_bounced = false; - - usb_gadget_unmap_request(&dwc->gadget, &req->request, - req->direction); + unmap_after_complete = true; + } else { + usb_gadget_unmap_request(&dwc->gadget, + &req->request, req->direction); + } dev_dbg(dwc->dev, "request %p from %s completed %d/%d ===> %d\n", req, dep->name, req->request.actual, @@ -273,6 +282,10 @@ void dwc3_gadget_giveback(struct dwc3_ep spin_unlock(&dwc->lock); usb_gadget_giveback_request(&dep->endpoint, &req->request); spin_lock(&dwc->lock); + + if (unmap_after_complete) + usb_gadget_unmap_request(&dwc->gadget, + &req->request, req->direction); } int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)