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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5497EC433EF for ; Mon, 30 May 2022 15:50:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241566AbiE3Puk (ORCPT ); Mon, 30 May 2022 11:50:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242042AbiE3PuC (ORCPT ); Mon, 30 May 2022 11:50:02 -0400 Received: from mail-wr1-x432.google.com (mail-wr1-x432.google.com [IPv6:2a00:1450:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 297806B000 for ; Mon, 30 May 2022 08:13:36 -0700 (PDT) Received: by mail-wr1-x432.google.com with SMTP id k16so10726719wrg.7 for ; Mon, 30 May 2022 08:13:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-transfer-encoding; bh=ShWA5Lf0IpnRT/XMhhsf2/+2EvIbcOqOmelUR0srNOc=; b=AVap6MTvKL8EUOtxSsbeFx/oS7vr6T58xi77FurdF+yckI3eVzLyhv/kZza1SpGPMs iTweZHGgyaqx0uAQyBgGt0apu0+S39Tqdpr/C8BrzJhSsbclxVFKbz9QJU9QK9y4OvXK /b/JtXyrHr0rjT1ekKRzzZ+fCMkoBzbLCwm3oUPkUaupadGhprLqzSgjji35kAJTj7ue BVNgtsd2qMnR6BDOlQFZ68NCNsImXh+3mMaGYExhel7n3UahQc17ds95uS3if/g6xakk jRZbnh7pO6rCwndwbDgP7ZUZ0etEL69Pc9+a+SL60fBrJiGomCV5xif0g9L76H8l9LlV yl8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-transfer-encoding; bh=ShWA5Lf0IpnRT/XMhhsf2/+2EvIbcOqOmelUR0srNOc=; b=ZxAh6e/4+e1/arIPfqWKguyoyKowLLXxR5sqWhSiTqkT31JmWf03tjzG/v+n0/TmO7 g57k83W6cAmqmkP5ni4dW+tShRCry839JIX5q8XZSmzTsgwNmuHOR352dU+r1aa9fs+9 kks6aHG3vobRy+bS5Vd2EEYb4k0qf+Qj0cSkM+ypfpf2tpuo0ThxjNqqTMQqJenXweOK IlHVn5PB6jRZvJtbAlABMP9kn6/f+9ACZmVdLIFgv62v7BiwmUAdDhQcz72nMbC9mTVd fdncMz0Ho2vQ8eDL2sdpUS7RbWrMTtlQK2dXfnd1bqxchkOpW6uhZIrYtzjKjbUUOsy8 wx7g== X-Gm-Message-State: AOAM5325kegLXGNl6HtvyLQPQXf8Aj5ZlRKu+EBGNObdn+C1oasRGvK9 62sCT0tVzl00xwaN3Xx0Sm78HVKZ1Sg= X-Google-Smtp-Source: ABdhPJycjThRvVXA4TdgZGtCguNCNnJmMgh0NeSrVoGYQoxN2AdcaQpJZxsyR8DfdIBQA3s7RaI9XA== X-Received: by 2002:adf:e198:0:b0:210:4e7:f57b with SMTP id az24-20020adfe198000000b0021004e7f57bmr19518989wrb.296.1653923614640; Mon, 30 May 2022 08:13:34 -0700 (PDT) Received: from [109.186.23.63] (109-186-23-63.bb.netvision.net.il. [109.186.23.63]) by smtp.gmail.com with ESMTPSA id w15-20020a5d680f000000b0021033ba8b15sm3208679wru.44.2022.05.30.08.13.33 (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 30 May 2022 08:13:34 -0700 (PDT) Message-ID: <6294DED6.70904@gmail.com> Date: Mon, 30 May 2022 18:12:22 +0300 From: Eli Billauer User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12) Gecko/20100907 Fedora/3.0.7-1.fc12 Thunderbird/3.0.7 MIME-Version: 1.0 To: Zheyu Ma CC: arnd@arndb.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] char: xillybus: Check endpoint type at probe time References: <20220529065839.3817434-1-zheyuma97@gmail.com> In-Reply-To: <20220529065839.3817434-1-zheyuma97@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/05/22 09:58, Zheyu Ma wrote: > static int xillyusb_setup_base_eps(struct xillyusb_dev *xdev) > { > + int ret; > + struct usb_endpoint_descriptor *in, *out; > + > + ret = usb_find_common_endpoints(xdev->intf->cur_altsetting,&in,&out, NULL, NULL); > + if (ret) > + return ret; > + > + if (in->bEndpointAddress != (IN_EP_NUM | USB_DIR_IN) || > + out->bEndpointAddress != (MSG_EP_NUM | USB_DIR_OUT)) > + return -EINVAL; > + > As far as I understand, this finds the first BULK endpoints in both directions, and verifies that their addresses are MSG_EP_NUM and IN_EP_NUM. Because both of these happen to equal 1, I suppose this indeed checks the right thing. But am I right that this won't work if either MSG_EP_NUM or IN_EP_NUM have a value that isn't 1? Not that I think that will ever happen, but still. > +static int xillyusb_check_endpoint(struct xillyusb_dev *xdev, u8 addr) > +{ > + int i; > + struct usb_host_interface *if_desc = xdev->intf->altsetting; > + > + for (i = 0; i< if_desc->desc.bNumEndpoints; i++) { > + struct usb_endpoint_descriptor *ep =&if_desc->endpoint[i].desc; > + > + if (ep->bEndpointAddress == addr&& usb_endpoint_is_bulk_out(ep)) > + return 0; > + } > + > + return -EINVAL; > +} > + > > Given that you've added this function, why isn't it used in xillyusb_setup_base_eps()? Thanks, Eli