From patchwork Mon Jun 3 07:11:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Chen X-Patchwork-Id: 10972443 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E95E2933 for ; Mon, 3 Jun 2019 07:10:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D626726E40 for ; Mon, 3 Jun 2019 07:10:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C97B527B13; Mon, 3 Jun 2019 07:10:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6126C26E40 for ; Mon, 3 Jun 2019 07:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726964AbfFCHKQ (ORCPT ); Mon, 3 Jun 2019 03:10:16 -0400 Received: from inva020.nxp.com ([92.121.34.13]:43318 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726383AbfFCHKQ (ORCPT ); Mon, 3 Jun 2019 03:10:16 -0400 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id D44181A039B; Mon, 3 Jun 2019 09:10:13 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 209521A00B1; Mon, 3 Jun 2019 09:10:10 +0200 (CEST) Received: from localhost.localdomain (mega.ap.freescale.net [10.192.208.232]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 93953402CF; Mon, 3 Jun 2019 15:10:05 +0800 (SGT) From: Peter Chen To: linux-usb@vger.kernel.org Cc: linux-imx@nxp.com, Peter Chen , stable@vger.kernel.org, Fabio Estevam , Greg KH , Sergei Shtylyov , Jun Li Subject: [PATCH v3 1/1] usb: chipidea: udc: workaround for endpoint conflict issue Date: Mon, 3 Jun 2019 15:11:37 +0800 Message-Id: <20190603071137.31013-1-peter.chen@nxp.com> X-Mailer: git-send-email 2.17.1 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP An endpoint conflict occurs when the USB is working in device mode during an isochronous communication. When the endpointA IN direction is an isochronous IN endpoint, and the host sends an IN token to endpointA on another device, then the OUT transaction may be missed regardless the OUT endpoint number. Generally, this occurs when the device is connected to the host through a hub and other devices are connected to the same hub. The affected OUT endpoint can be either control, bulk, isochronous, or an interrupt endpoint. After the OUT endpoint is primed, if an IN token to the same endpoint number on another device is received, then the OUT endpoint may be unprimed (cannot be detected by software), which causes this endpoint to no longer respond to the host OUT token, and thus, no corresponding interrupt occurs. There is no good workaround for this issue, the only thing the software could do is numbering isochronous IN from the highest endpoint since we have observed most of device number endpoint from the lowest. Cc: #v3.14+ Cc: Fabio Estevam Cc: Greg KH Cc: Sergei Shtylyov Cc: Jun Li Signed-off-by: Peter Chen --- Changes for v3: - Using MACRO to simply the code - One tiny code style issue Changes for v2: - Improve the code sytle drivers/usb/chipidea/udc.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index 829e947cabf5..6a5ee8e6da10 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -1622,6 +1622,25 @@ static int ci_udc_pullup(struct usb_gadget *_gadget, int is_on) static int ci_udc_start(struct usb_gadget *gadget, struct usb_gadget_driver *driver); static int ci_udc_stop(struct usb_gadget *gadget); + +/* Match ISOC IN from the highest endpoint */ +static struct usb_ep *ci_udc_match_ep(struct usb_gadget *gadget, + struct usb_endpoint_descriptor *desc, + struct usb_ss_ep_comp_descriptor *comp_desc) +{ + struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget); + struct usb_ep *ep; + + if (usb_endpoint_xfer_isoc(desc) && usb_endpoint_dir_in(desc)) { + list_for_each_entry_reverse(ep, &ci->gadget.ep_list, ep_list) { + if (ep->caps.dir_in && !ep->claimed) + return ep; + } + } + + return NULL; +} + /** * Device operations part of the API to the USB controller hardware, * which don't involve endpoints (or i/o) @@ -1635,6 +1654,7 @@ static const struct usb_gadget_ops usb_gadget_ops = { .vbus_draw = ci_udc_vbus_draw, .udc_start = ci_udc_start, .udc_stop = ci_udc_stop, + .match_ep = ci_udc_match_ep, }; static int init_eps(struct ci_hdrc *ci)