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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 59F23C433E0 for ; Tue, 4 Aug 2020 15:51:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F058208A9 for ; Tue, 4 Aug 2020 15:51:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596556276; bh=OtA0EW8iaXuoVIFAIgh1KuT3uEjn0AAO/2QdeC/r5FA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=k8zlLOtEIK619H+DYQVl4zBAkJdhBXc3aUz+6FZuO8NttMA3hk7n8csvZKeI1rb80 nDRsuqsEtYu3Nfr1JjBBSDIUx2oibhPJw4Ab1mHaulkJyKhl5StNnjQ5Bvy1dNvdwK AlPXoxxmXuu/PFadnQ9F/0/xVhajfBMuEoC4Zkg0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729206AbgHDPvH (ORCPT ); Tue, 4 Aug 2020 11:51:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:55458 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728157AbgHDPvB (ORCPT ); Tue, 4 Aug 2020 11:51:01 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 38C4F208A9; Tue, 4 Aug 2020 15:51:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596556260; bh=OtA0EW8iaXuoVIFAIgh1KuT3uEjn0AAO/2QdeC/r5FA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rdNvOcx/C/QBAmmNbx2kEz7HV7AG9W6G/LHdx67gZbzUj6EBVIXA+Xzl5Ln9iwRol Dk/vWrU+PEqGDGTGOxxue63JHVdSYIM7lKHgBq1XL9wW/63bp4g3MYScoDdlnSkNGr xzTh1LQol6MghcQajeEM7cJ4eudzb584hPevBoXM= Date: Tue, 4 Aug 2020 17:51:20 +0200 From: Greg Kroah-Hartman To: Daniel Gutson Cc: Derek Kiernan , Tudor Ambarus , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Mika Westerberg , Arnd Bergmann , Mauro Carvalho Chehab , linux-kernel , Richard Hughes , Alex Bazhaniuk Subject: Re: [PATCH] Platform lockdown information in SYSFS Message-ID: <20200804155120.GA496635@kroah.com> References: <20200731070053.GC1518178@kroah.com> <20200731141503.GA1717752@kroah.com> <20200804064154.GE696690@kroah.com> <20200804142250.GA247448@kroah.com> <20200804144414.GA50022@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 04, 2020 at 12:05:25PM -0300, Daniel Gutson wrote: > On Tue, Aug 4, 2020 at 11:43 AM Greg Kroah-Hartman > wrote: > > > > On Tue, Aug 04, 2020 at 11:37:02AM -0300, Daniel Gutson wrote: > > > On Tue, Aug 4, 2020 at 11:23 AM Greg Kroah-Hartman < > > > gregkh@linuxfoundation.org> wrote: > > > > > > > > On Tue, Aug 04, 2020 at 10:50:13AM -0300, Daniel Gutson wrote: > > > > > On Tue, Aug 4, 2020 at 3:41 AM Greg Kroah-Hartman > > > > > wrote: > > > > > > > > > > > > On Mon, Aug 03, 2020 at 07:04:56PM -0300, Daniel Gutson wrote: > > > > > > > > > > Think of this as an input device. You don't put the random > > > input > > > > > > > > > > attributes all in one place, you create a new device that > > > represents the > > > > > > > > > > input interface and register that. > > > > > > > > > > > > > > I'm having trouble with this. What's the dev_t for the child > > > devices? > > > > > > > I'm doing > > > > > > > child_device = device_create(&my_class, &pdev->dev, MKDEV(0, 0), > > > > > > > NULL, "child"); > > > > > > > pdev is the pci_device (intel-spi-pci) > > > > > > > dmesg shows > > > > > > > > > > > > > > sysfs: cannot create duplicate filename '/class/my-class' > > > > > > > (call trace) > > > > > > > kobject_add_internal failed for my-class with -EEXIST, don't try > > > > > > > to register things with the same name in the same directory. > > > > > > > > > > > > Without seeing all of your code, I can't tell you what you are doing > > > > > > wrong, but the kernel should be giving you a huge hint here... > > > > > > > > > > > > Don't create duplicate names in the same subdirectory. > > > > > > > > > > I'm not doing that. One of my questions is if MKDEV(0, 0) is valid for > > > > > create_device, which I inferred so from the documentation. > > > > > > > > Yes it is, but that's not the error given to you :) > > > > > > > > Many in-kernel users call device_create() with MKDEV(0, 0) > > > > > > > > > Here is the listing > > > > > > > > > > > > > > > > It's not in any format to read, please never strip leading whitespace, > > > > it hurts my brain... > > > > > > (trying again) > > > Also, this is in pastebin: https://pastebin.com/8Ye9eUm5 > > > > > > #include > > > #include > > > #include > > > #include > > > #include > > > #include > > > #include > > > #include > > > > > > static ssize_t howareyou_show(struct class *class, struct class_attribute > > > *attr, > > > char *buf) > > > { > > > return sprintf(buf, "%s\n", "How are you?"); > > > } > > > static CLASS_ATTR_RO(howareyou); > > > > These are rare, as they are "global" for a class, are you sure you want > > that? > > I'm no longer using class attributes, this is from my previous > experiment. Sorry for the confusion. > In the "real" code I'll use DEVICE_ATTR_RO. > > > > > > > > > static struct class my_class = { > > > .name = "my-class", > > > .owner = THIS_MODULE, > > > }; > > > > > > struct device* child_device; > > > > > > static int mypci_probe(struct pci_dev *pdev, > > > const struct pci_device_id *id) > > > { > > > int ret; > > > > > > ret = pcim_enable_device(pdev); > > > if (ret) > > > return ret; > > > > > > ret = class_register(&my_class); > > > if (ret < 0) > > > return ret; > > > > > > > > > pr_info("DFG: Recognized. DID: %lx\n", (unsigned long > > > int)id->driver_data); > > > pr_info("DFG: device DID: %lx\n", (unsigned long int)pdev->device); > > > > > > ret = class_create_file(&my_class, &class_attr_howareyou); > > > if (ret != 0) { > > > pr_err("DFG class create file error: %d\n", ret); > > > class_unregister(&my_class); > > > return ret; > > > } > > > > > > child_device = device_create(&my_class, &pdev->dev, MKDEV(0, 0), > > > NULL, "child"); > > > if (child_device == NULL) { > > > pr_err("DFG error child device NULL"); > > > } > > > > > > return ret; > > > } > > > > > > > > > Looks sane, what does your kernel log say when you load this? > first insmod, OK. > rmmod, OK. > Second insmod: > > [ 4149.389133] sysfs: cannot create duplicate filename > '/devices/pci0000:00/0000:00:1f.0/my-class' Ok, that means you did not clean up properly. After rmmod see if you really did clean up all of the directories/files you created. The kernel is trying to be nice and give you a hint here :) thanks, greg k-h