From patchwork Mon Jun 17 01:49:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Chen X-Patchwork-Id: 10997731 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 CC5CA14C0 for ; Mon, 17 Jun 2019 01:47:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BDA442880D for ; Mon, 17 Jun 2019 01:47:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AEB1C28815; Mon, 17 Jun 2019 01:47:24 +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 174422880D for ; Mon, 17 Jun 2019 01:47:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727529AbfFQBrX (ORCPT ); Sun, 16 Jun 2019 21:47:23 -0400 Received: from inva021.nxp.com ([92.121.34.21]:35748 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727481AbfFQBrW (ORCPT ); Sun, 16 Jun 2019 21:47:22 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id F3651200B3A; Mon, 17 Jun 2019 03:47:20 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 9BDA5200B38; Mon, 17 Jun 2019 03:47:17 +0200 (CEST) Received: from localhost.localdomain (mega.ap.freescale.net [10.192.208.232]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 87604402D6; Mon, 17 Jun 2019 09:47:13 +0800 (SGT) From: Peter Chen To: gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, Peter Chen , stable@vger.kernel.org, Fabio Estevam , Sergei Shtylyov , Jun Li Subject: [PATCH 1/1] usb: chipidea: udc: workaround for endpoint conflict issue Date: Mon, 17 Jun 2019 09:49:07 +0800 Message-Id: <20190617014907.9184-2-peter.chen@nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190617014907.9184-1-peter.chen@nxp.com> References: <20190617014907.9184-1-peter.chen@nxp.com> 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 --- 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)