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 8DF03C4332F for ; Thu, 6 Jan 2022 18:14:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242480AbiAFSOP (ORCPT ); Thu, 6 Jan 2022 13:14:15 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:57816 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241192AbiAFSOM (ORCPT ); Thu, 6 Jan 2022 13:14:12 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4870561D17; Thu, 6 Jan 2022 18:14:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A780C36AEB; Thu, 6 Jan 2022 18:14:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641492850; bh=pk9c3vFsS24A9H9YRNmuoLU04tTgveyiSfxz/RguLrg=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=tWL9ah320xPJ7ZLvQrLFkjIeV1LTlPrJ2qSY/t0fKFbU+5MxnpWBBUesVfIjO0xOO l+Yvi8TANgRjNK2vReZYRlLqehfzP4qE2oNJarfvWixIS0OfQkuKWpI6rrQEfWGn25 oroVHI/IQA8JEpMkHqxWMkHxAKg+IVXn/Zqji7RoVtpWyymeRt5WcM4qay0A7EFOWe jnI4JpbaAmAttF9a/Yhl/wWUUgx6A1s8zF9Wpc8ft5Y9hFSMLv91rRujQQ/od6scnA LsHiF+8iYMGoQ6RcvIn/+ZU8WqHN0Y3LnsXMJdYHRbXi/+K/WGfnGi+pM9zExj10bs +smYL/+iBYHZg== Date: Thu, 6 Jan 2022 12:14:09 -0600 From: Bjorn Helgaas To: John Garry Cc: Niklas Schnelle , Mauro Carvalho Chehab , Arnd Bergmann , Hans Verkuil , Ettore Chimenti , Greg Kroah-Hartman , Arnd Bergmann , Bjorn Helgaas , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren , Damien Le Moal , Ian Abbott , H Hartley Sweeten , Linus Walleij , Bartosz Golaszewski , Jean Delvare , Guenter Roeck , Dmitry Torokhov , Karsten Keil , Sathya Prakash , Sreekanth Reddy , Suganath Prabu Subramani , Michael Grzeschik , "David S. Miller" , Jakub Kicinski , Jesse Brandeburg , Tony Nguyen , Kalle Valo , Jouni Malinen , "James E.J. Bottomley" , "Martin K. Petersen" , Hannes Reinecke , Kashyap Desai , Sumit Saxena , Shivasharan S , Nilesh Javali , GR-QLogic-Storage-Upstream@marvell.com, Mark Brown , Sudip Mukherjee , Teddy Wang , Forest Bond , Jiri Slaby , Wim Van Sebroeck , Jaroslav Kysela , Takashi Iwai , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-pci@vger.kernel.org, linux-riscv@lists.infradead.org, linux-csky@vger.kernel.org, linux-ide@vger.kernel.org, linux-gpio@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-i2c@vger.kernel.org, linux-input@vger.kernel.org, netdev@vger.kernel.org, linux-media@vger.kernel.org, MPT-FusionLinux.pdl@broadcom.com, linux-scsi@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-wireless@vger.kernel.org, megaraidlinux.pdl@broadcom.com, linux-spi@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-serial@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-watchdog@vger.kernel.org Subject: Re: [RFC 01/32] Kconfig: introduce and depend on LEGACY_PCI Message-ID: <20220106181409.GA297735@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <74bf4fde-3972-1c36-ca04-58089da0d82b@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org On Thu, Jan 06, 2022 at 05:41:00PM +0000, John Garry wrote: > On 05/01/2022 19:47, Bjorn Helgaas wrote: > > IMO inb() should > > be present but do something innocuous like return ~0, as it would if > > I/O port space is supported but there's no device at that address. > > > > [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/megaraid.c?id=v5.15#n4210 > > > > That driver would prob not be used on systems which does not support PIO, > and so could have a HAS_IOPORT dependency. But it is not strictly necessary. I don't want the path of "this driver isn't needed because the device is unlikely to be used on this arch." Maybe it's not _always_ possible, but if the device can be plugged into the platform, I think we should be able to build the driver for it. If the device requires I/O port space and the platform doesn't support it, the PCI core or the driver should detect that and give a useful diagnostic. Bjorn