From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FF95C28CC2 for ; Thu, 30 May 2019 06:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 040DB25A89 for ; Thu, 30 May 2019 06:43:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727402AbfE3GnT (ORCPT ); Thu, 30 May 2019 02:43:19 -0400 Received: from inva021.nxp.com ([92.121.34.21]:41920 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725961AbfE3GnT (ORCPT ); Thu, 30 May 2019 02:43:19 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id B333F2005ED; Thu, 30 May 2019 08:43:16 +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 261A9200156; Thu, 30 May 2019 08:43:14 +0200 (CEST) Received: from localhost.localdomain (mega.ap.freescale.net [10.192.208.232]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 97541402B5; Thu, 30 May 2019 14:43:10 +0800 (SGT) From: Peter Chen To: linux-usb@vger.kernel.org Cc: linux-imx@nxp.com, Peter Chen , stable@vger.kernel.org, Jun Li Subject: [PATCH 1/1] usb: chipidea: udc: workaround for endpoint conflict issue Date: Thu, 30 May 2019 14:45:05 +0800 Message-Id: <20190530064505.6292-1-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 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: Jun Li Signed-off-by: Peter Chen --- Changes for v2: - Some coding style improvements drivers/usb/chipidea/udc.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index 829e947cabf5..411d387a45c9 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -1622,6 +1622,29 @@ 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; + u8 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; + + if ((type == USB_ENDPOINT_XFER_ISOC) && + (desc->bEndpointAddress & USB_DIR_IN)) { + 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 +1658,7 @@ 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) -- 2.14.1