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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 CD528C433DF for ; Wed, 13 May 2020 17:05:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C34E205ED for ; Wed, 13 May 2020 17:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589389509; bh=CjEfXpPIH7XRzomP1iu377biV+QAATQ4yh1cf6voOCo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=pD/JbXj1nuXa1NXTbKEl59+8jlR3Il9dcz5wnjmYyEVmkdk1dre8O2Pg14dyOgUDw X/DkO9BVbO3IvVGx5rqi/VtEtRcTv2ppExfaX0GFoKkEMjYyQxVEMvf6fDtIn1thnf n+MNPIMNkhgH6JPDXiHBH1e4qxpn5nQpOnLKPEPo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389852AbgEMRFI (ORCPT ); Wed, 13 May 2020 13:05:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:37340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728068AbgEMRFH (ORCPT ); Wed, 13 May 2020 13:05:07 -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 30843205CB; Wed, 13 May 2020 17:05:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589389507; bh=CjEfXpPIH7XRzomP1iu377biV+QAATQ4yh1cf6voOCo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nr4PpmZDc4mu0yzGbKsiz8SoJD/n2BPo2hncfqdP84nMAjaD6O427NP9viYwFL8AC he8MEW3BBis8pDwqC3Ifa2pw63G2cHvak4kzKZwlW0TxjcZ1bIr13yS8nxVtp6FLs1 6QAzGRQkMMIaShw+z/DOUqizo/fGGg4nB9ypQCM4= Date: Wed, 13 May 2020 19:05:05 +0200 From: Greg Kroah-Hartman To: Florian Fainelli Cc: Al Cooper , linux-kernel@vger.kernel.org, Alan Stern , Andy Shevchenko , bcm-kernel-feedback-list@broadcom.com, devicetree@vger.kernel.org, Krzysztof Kozlowski , linux-usb@vger.kernel.org, Mathias Nyman , Rob Herring , Yoshihiro Shimoda , Andy Shevchenko Subject: Re: [PATCH v10 1/5] usb: xhci: Change the XHCI link order in the Makefile Message-ID: <20200513170505.GB1369204@kroah.com> References: <20200512150019.25903-1-alcooperx@gmail.com> <20200512150019.25903-2-alcooperx@gmail.com> <20200513122613.GA1023594@kroah.com> <7acc2a4c-caab-11e7-7b3f-4176f19c58cf@gmail.com> <20200513162723.GF1362525@kroah.com> <38ff034d-a84c-2309-a8d5-f344930d9a31@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <38ff034d-a84c-2309-a8d5-f344930d9a31@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2020 at 09:31:11AM -0700, Florian Fainelli wrote: > > > On 5/13/2020 9:27 AM, Greg Kroah-Hartman wrote: > > On Wed, May 13, 2020 at 08:08:07AM -0700, Florian Fainelli wrote: > >> > >> > >> On 5/13/2020 5:26 AM, Greg Kroah-Hartman wrote: > >>> On Tue, May 12, 2020 at 11:00:15AM -0400, Al Cooper wrote: > >>>> Some BRCMSTB USB chips have an XHCI, EHCI and OHCI controller > >>>> on the same port where XHCI handles 3.0 devices, EHCI handles 2.0 > >>>> devices and OHCI handles <2.0 devices. Currently the Makefile > >>>> has XHCI linking at the bottom which will result in the XHIC driver > >>>> initalizing after the EHCI and OHCI drivers and any installed 3.0 > >>>> device will be seen as a 2.0 device. Moving the XHCI linking > >>>> above the EHCI and OHCI linking fixes the issue. > >>> > >>> What happens if all of these are modules and they are loaded in a > >>> different order? This makefile change will not help with that, you need > >>> to have logic in the code in order to properly coordinate this type of > >>> mess, sorry. > >> > >> I believe we should be using module soft dependencies to instruct the > >> module loaders to load the modules in the correct order, so something > >> like this would do (not tested) for xhci-plat-hcd.c: > >> > >> MODULE_SOFTDEP("post: ehci-hcd ohci-hcd"); > >> > >> and I am not sure whether we need to add the opposite for ehci-hcd and > >> ohci-hcd: > >> > >> MODULE_SOFTDEP("pre: xhci-plat-hcd"); > > > > That's a nice start, but what happens if that isn't honored? This > > really needs to work properly for any order as you never can guarantee > > module/driver loading order in a system of modules. > > I also suggested that device links may help, though I am not sure. What > do you suggest to be done? No idea. device links will help if you defer the probe properly until you see the proper drivers binding correctly. good luck! greg k-h