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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1459AC433F5 for ; Wed, 12 Jan 2022 15:33:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=pG+vOat/PgeWV/pdPJLy1V0Ebbm0HBp7VlPhV2Oz2Oo=; b=rqPQ6yMy3lsvBs CpWMvrh7fOwzvxvI/Jmmjzzad2SxCF/S2JcnZSDHvZtC1MOY/atRFhjRPWDMhGE5I+9yG9+eMsHHc D60CRAAQK7QFePx79SMqJB3u4FpUXuhImPGUqhQnkflQ9PuisiFhPBuFUGzZp5djAImk0I0Zpzrid KDrSMxZZ+xObLExPsKk3ijqGl2/TpWRelT+aOIrTnPJs0d1+M6kfgiXEFilyYfYVafkH5p2qV/X/f 6iB9Xb+eR555tL6GEymaSCNT0/WS4792dz1aEINl4i1sYnaOzNi1NSAjfaIh7lcYgyRg2wkIv5IRa u+1XXAtWODygGtzfpipg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n7fcJ-002vy1-E2; Wed, 12 Jan 2022 15:32:51 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n7fcC-002vw7-Mb for linux-arm-kernel@lists.infradead.org; Wed, 12 Jan 2022 15:32:46 +0000 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 EEC8B618B8; Wed, 12 Jan 2022 15:32:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08895C36AE5; Wed, 12 Jan 2022 15:32:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642001562; bh=TmVoPyrYCTfNSodHZ3UduskHBWm/lkWLvgSm8FdlN7M=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=OOcmWvbFWt0+bDrg1D6Bu2Ep5/ae0/OMi1woG2R9lLudTKIevYAeEQIUKgGh/trhD zZUC7IuwPAAqpCZTnPAq/ZQ4zhUjS/3SgoOeZ/QpThJlwZZH6jXgk1SfCgtZWbvh0q K3RbifkUmhQXdM4GDFoV4B9l1p/poQoeKndCAMP2zazWnJc4BhRuguSm6N66nipAO7 wjZ4/VecDAF+iuzHXNxg7ksnCukSGEUbPp3nPfJ3qALcZl+SSCqIdfc8yl7oV+9hcV BcozVK5KBI+lWfa7rDihqlQjCZ/D3C94+RA+KQJj2hkPWjUjiA4N4sdyYDzXS1hW2w wPBMlbRnFmZWg== Date: Wed, 12 Jan 2022 09:32:40 -0600 From: Bjorn Helgaas To: Rob Herring Cc: Lorenzo Pieralisi , Jonathan Hunter , Thierry Reding , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Tiezhu Yang , Jiaxun Yang , Huacai Chen , Ray Jui , Scott Branden , "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , linux-arm-kernel , PCI , linux-tegra Subject: Re: [PATCH 19/19] PCI: Set bridge map_irq and swizzle_irq to default functions Message-ID: <20220112153240.GA258585@bhelgaas> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220112_073244_811497_0A69C275 X-CRM114-Status: GOOD ( 24.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jan 12, 2022 at 09:09:31AM -0600, Rob Herring wrote: > On Tue, Jan 11, 2022 at 3:46 PM Bjorn Helgaas wrote: > > On Tue, Jul 21, 2020 at 08:25:14PM -0600, Rob Herring wrote: > > > The majority of DT based host drivers use the default .map_irq() and > > > .swizzle_irq() functions, so let's initialize the function pointers to > > > the default and drop setting them in the host drivers. > > > > > > Drivers like iProc which don't support legacy interrupts need to set > > > .map_irq() back to NULL. > > > > Probably a dumb question... > > > > This patch removed all the ->swizzle_irq users in drivers/pci/, which > > is great -- IIUC swizzling is specified by the PCI-to-PCI Bridge Spec, > > r1.2, sec 9.1, and should not be device-specific. I assume the few > > remaining arch/ users (arm and alpha) are either bugs or workarounds > > for broken devices. > > > > My question is why we still have a few users of ->map_irq: loongson, > > tegra, iproc. Shouldn't this mapping be described somehow via DT? > > Tegra could perhaps be written another way. The mapping is standard, > but it's disabling an idle state when PCI interrupts are used. It just > needs some way to know if legacy interrupts are being used. > > iproc looks pretty special with its bcma bus. > > Adding something to DT doesn't really help because we'd still have to > support the old way. I guess my underlying question is whether new drivers should ever use ->swizzle_irq() and ->map_irq(). I'm hoping the answer is "no". If we need them for pre-DT systems or things with incomplete DTs in the field, I guess we have to live with that. All ACPI really gives you is the _PRT, and I'm not sure that's expressive enough to describe platforms that need these things, so maybe this will eventually solve itself. Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel