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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 C3E9FC04AA7 for ; Mon, 13 May 2019 10:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0B4D208CA for ; Mon, 13 May 2019 10:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728584AbfEMKGl convert rfc822-to-8bit (ORCPT ); Mon, 13 May 2019 06:06:41 -0400 Received: from unicorn.mansr.com ([81.2.72.234]:36228 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727339AbfEMKGl (ORCPT ); Mon, 13 May 2019 06:06:41 -0400 Received: by unicorn.mansr.com (Postfix, from userid 51770) id D154B149B5; Mon, 13 May 2019 11:06:39 +0100 (BST) From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Marek Szyprowski Cc: Peter Chen , "linux-usb\@vger.kernel.org" , "linux-samsung-soc\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" , Greg Kroah-Hartman , Bartlomiej Zolnierkiewicz , Markus Reichl , Krzysztof Kozlowski Subject: Re: [PATCH v3] usb: core: verify devicetree nodes for USB devices References: <20190509084726.5405-1-m.szyprowski@samsung.com> <7c5579d2-634a-d705-a451-563939957d57@samsung.com> <3544eb61-2bd8-338d-8d62-d95a775528ef@samsung.com> <5d0abe9c-613c-d39b-6746-78e5e5c2bbc5@samsung.com> Date: Mon, 13 May 2019 11:06:39 +0100 In-Reply-To: <5d0abe9c-613c-d39b-6746-78e5e5c2bbc5@samsung.com> (Marek Szyprowski's message of "Mon, 13 May 2019 12:03:18 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Marek Szyprowski writes: > Hi Peter, > > On 2019-05-13 11:23, Peter Chen wrote: >>> On 2019-05-13 11:00, Peter Chen wrote: >>>>> On 2019-05-10 05:10, Peter Chen wrote: >>>>>>> Marek Szyprowski writes: >>>>>>>> Commit 69bec7259853 ("USB: core: let USB device know device node") >>>>>>>> added support for attaching devicetree node for USB devices. The >>>>>>>> mentioned commit however identifies the given USB device node only >>>>>>>> by the >>>>> 'reg' >>>>>>>> property in the host controller children nodes. The USB device >>>>>>>> node however also has to have a 'compatible' property as described >>>>>>>> in Documentation/devicetree/bindings/usb/usb-device.txt. Lack for >>>>>>>> the 'compatible' property check might result in assigning a >>>>>>>> devicetree node, which is not intended to be the proper node for the given >>> USB device. >>>>>>>> This is important especially when USB host controller has >>>>>>>> child-nodes for other purposes. For example, Exynos EHCI and OHCI >>>>>>>> drivers already define child-nodes for each physical root hub port >>>>>>>> and assigns respective PHY controller and parameters for them. >>>>>>>> Those binding predates support for USB devicetree nodes. >>>>>>>> >>>>>>>> Checking for the proper compatibility string allows to mitigate >>>>>>>> the conflict between USB device devicetree nodes and the bindings >>>>>>>> for USB controllers with child nodes. It also fixes the >>>>>>>> side-effect of the other commits, like 01fdf179f4b0 ("usb: core: >>>>>>>> skip interfaces disabled in devicetree"), which incorrectly >>>>>>>> disables some devices on Exynos based boards. >>>>>> Hi Marek, >>>>>> >>>>>> The purpose of your patch is do not set of_node for device under USB >>>>>> controller, >>>>> right? >>>>> >>>>> Right. >>>>> >>>> Do you mind doing it at function exynos_ehci_get_phy of ehci-exynos.c? >>> I don't mind fixing it in ehci-exynos, but frankly so far I have no >>> idea how to do it. The problem is that newly created USB devices >>> get of-node pointer pointing to a node which if not intended for >>> them. How this can be fixed in ehci-exynos? >>> >> >> Can't be workaround by setting of_node as NULL for EHCI controller or >> for PHY node at exynos_ehci_get_phy? > > Ah, such workaround? I will check, but this will need to be done with > care, because have a side effect for other subsystems like regulators or > clocks. > > BTW, What's wrong with proper, full verification of USB device nodes? Your approach so far doesn't address the actual problem of a conflict between the generic USB DT bindings and those for the Exynos host controller. If you fix that, the validation issue goes away. -- Måns Rullgård