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,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 E573EC4320A for ; Wed, 25 Aug 2021 13:38:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9A0A610E6 for ; Wed, 25 Aug 2021 13:38:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241293AbhHYNjL (ORCPT ); Wed, 25 Aug 2021 09:39:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:60744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240444AbhHYNjL (ORCPT ); Wed, 25 Aug 2021 09:39:11 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 E2959610FA; Wed, 25 Aug 2021 13:38:24 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mIt6k-0079Ci-Vi; Wed, 25 Aug 2021 14:38:23 +0100 Date: Wed, 25 Aug 2021 14:38:22 +0100 Message-ID: <87bl5lpru9.wl-maz@kernel.org> From: Marc Zyngier To: Barry Song <21cnbao@gmail.com> Cc: bhelgaas@google.com, tglx@linutronix.de, Jonathan.Cameron@huawei.com, bilbao@vt.edu, corbet@lwn.net, gregkh@linuxfoundation.org, leon@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxarm@huawei.com, luzmaximilian@gmail.com, mchehab+huawei@kernel.org, schnelle@linux.ibm.com, jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com, intel-wired-lan@lists.osuosl.org, Barry Song Subject: Re: [PATCH v3 3/3] PCI/MSI: remove msi_attrib.default_irq in msi_desc In-Reply-To: <20210825102636.52757-4-21cnbao@gmail.com> References: <20210825102636.52757-1-21cnbao@gmail.com> <20210825102636.52757-4-21cnbao@gmail.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: 21cnbao@gmail.com, bhelgaas@google.com, tglx@linutronix.de, Jonathan.Cameron@huawei.com, bilbao@vt.edu, corbet@lwn.net, gregkh@linuxfoundation.org, leon@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxarm@huawei.com, luzmaximilian@gmail.com, mchehab+huawei@kernel.org, schnelle@linux.ibm.com, jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com, intel-wired-lan@lists.osuosl.org, song.bao.hua@hisilicon.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, 25 Aug 2021 11:26:36 +0100, Barry Song <21cnbao@gmail.com> wrote: > > From: Marc Zyngier > > default_irq is hideous as it should be per-device but not per-desc. > On the other hand, MSI-X case doesn't use it at all. Since sysfs > IRQ has moved to use the msi_entry instead of pci_dev.irq, now it > seems it is safe to remove msi_attrib.default_irq. Thanks for doing the write-up. Maybe worth adding that drivers that use dev->irq while having enabled MSI will break (INTx will be disabled while MSI is enabled). That should give people a clue about what to fix when they bisect the problem to this patch. Also, a link to the discussion that lead to this patch would be useful to give some context. No need to respin this for now, let's give it a shake after 5.14. Thanks, M. -- Without deviation from the norm, progress is not possible.