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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 C9E85C31E46 for ; Wed, 12 Jun 2019 10:54:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9EC15208C2 for ; Wed, 12 Jun 2019 10:54:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407441AbfFLKyS (ORCPT ); Wed, 12 Jun 2019 06:54:18 -0400 Received: from foss.arm.com ([217.140.110.172]:50176 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406068AbfFLKyS (ORCPT ); Wed, 12 Jun 2019 06:54:18 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0017028; Wed, 12 Jun 2019 03:54:17 -0700 (PDT) Received: from redmoon (unknown [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B18973F246; Wed, 12 Jun 2019 03:55:57 -0700 (PDT) Date: Wed, 12 Jun 2019 11:54:10 +0100 From: Lorenzo Pieralisi To: Marc Zyngier Cc: "Z.q. Hou" , "mark.rutland@arm.com" , "devicetree@vger.kernel.org" , Xiaowei Bao , "linux-pci@vger.kernel.org" , "l.subrahmanya@mobiveil.co.in" , "will.deacon@arm.com" , "linux-kernel@vger.kernel.org" , Leo Li , "M.h. Lian" , "robh+dt@kernel.org" , Mingkai Hu , "catalin.marinas@arm.com" , "bhelgaas@google.com" , "shawnguo@kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCHv5 04/20] PCI: mobiveil: Remove the flag MSI_FLAG_MULTI_PCI_MSI Message-ID: <20190612105410.GA9918@redmoon> References: <20190412083635.33626-1-Zhiqiang.Hou@nxp.com> <20190412083635.33626-5-Zhiqiang.Hou@nxp.com> <20190611165935.GA22836@redmoon> <3b883516-1d63-1504-bdc9-22ac9c6f2d46@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3b883516-1d63-1504-bdc9-22ac9c6f2d46@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Jun 11, 2019 at 06:29:49PM +0100, Marc Zyngier wrote: > On 11/06/2019 17:59, Lorenzo Pieralisi wrote: > > On Fri, Apr 12, 2019 at 08:35:36AM +0000, Z.q. Hou wrote: > >> From: Hou Zhiqiang > >> > >> The current code does not support multiple MSIs, so remove > >> the corresponding flag from the msi_domain_info structure. > > > > Please explain me what's the problem before removing multi MSI > > support. > > The reason seems to be the following code in the allocator: > > WARN_ON(nr_irqs != 1); > mutex_lock(&msi->lock); > > bit = find_first_zero_bit(msi->msi_irq_in_use, msi->num_of_vectors); > if (bit >= msi->num_of_vectors) { > mutex_unlock(&msi->lock); > return -ENOSPC; > } > > set_bit(bit, msi->msi_irq_in_use); > > So instead of fixing the allocator, the author prefers disabling > the feature. I'm not sure whether that is an acceptable outcome... :) No it is not that's why I asked and I am waiting for an answer. Lorenzo