Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755609AbdDJQwK (ORCPT ); Mon, 10 Apr 2017 12:52:10 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36272 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755571AbdDJQwI (ORCPT ); Mon, 10 Apr 2017 12:52:08 -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 4.10 063/110] usb: dwc3: gadget: delay unmap of bounced requests Date: Mon, 10 Apr 2017 18:42:54 +0200 Message-Id: <20170410164204.739775151@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170410164201.247583164@linuxfoundation.org> References: <20170410164201.247583164@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: 2048 Lines: 67 4.10-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 @@ -171,6 +171,7 @@ void dwc3_gadget_giveback(struct dwc3_ep int status) { struct dwc3 *dwc = dep->dwc; + unsigned int unmap_after_complete = false; req->started = false; list_del(&req->list); @@ -180,11 +181,19 @@ 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_by_dev(dwc->sysdev, - &req->request, req->direction); + unmap_after_complete = true; + } else { + usb_gadget_unmap_request_by_dev(dwc->sysdev, + &req->request, req->direction); + } trace_dwc3_gadget_giveback(req); @@ -192,6 +201,10 @@ void dwc3_gadget_giveback(struct dwc3_ep usb_gadget_giveback_request(&dep->endpoint, &req->request); spin_lock(&dwc->lock); + if (unmap_after_complete) + usb_gadget_unmap_request_by_dev(dwc->sysdev, + &req->request, req->direction); + if (dep->number > 1) pm_runtime_put(dwc->dev); }