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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 D3971C388F7 for ; Tue, 3 Nov 2020 09:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B7E722404 for ; Tue, 3 Nov 2020 09:54:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604397268; bh=+PMSBSh/qsbOxi/PGx0X2fcaxpuGi6w2e85VksrgH70=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=pt8EFqs947royucf5cMkyxWH9G3wEis+2sEVBdai3QbrSviEbkjqqVPjWNqLuNH4V NLm4YTk3FwBHU2+4fvKFFJ8jKMt4TCPNZljIxlqU1CE1RUxYXd8xlmVtwpSXGTXKoT AEt4bul+tIFWNS46I+ReZevij3fC6NFzBdSslHgU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727529AbgKCJy1 (ORCPT ); Tue, 3 Nov 2020 04:54:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:55002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725988AbgKCJy0 (ORCPT ); Tue, 3 Nov 2020 04:54:26 -0500 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 F1C3F2080C; Tue, 3 Nov 2020 09:54:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604397266; bh=+PMSBSh/qsbOxi/PGx0X2fcaxpuGi6w2e85VksrgH70=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=y5r7zekSZXihQG1+urqGj/cKRCuJEMUjeTlyba1YH27f4KbxZMsInaR1VZArSennh s4+p3GyqFuCLDhCcYBUVK2Pn3at2pBqcf0ReYAzF8BMA/iqfIxvh6o4eA7yti2DJMy AbyzLu2L9ZI0/yRbD45cLVXezL+6tqzn34eSfSrw= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kZt1D-0075JQ-RE; Tue, 03 Nov 2020 09:54:23 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 03 Nov 2020 09:54:23 +0000 From: Marc Zyngier To: Thomas Gleixner Cc: Frank Wunderlich , Ryder Lee , linux-mediatek@lists.infradead.org, Frank Wunderlich , linux-kernel@vger.kernel.org, Matthias Brugger , linux-pci@vger.kernel.org, Bjorn Helgaas Subject: Re: Aw: Re: [PATCH] pci: mediatek: fix warning in msi.h In-Reply-To: <877dr38kt8.fsf@nanos.tec.linutronix.de> References: <20201031140330.83768-1-linux@fw-web.de> <878sbm9icl.fsf@nanos.tec.linutronix.de> <87lfflti8q.wl-maz@kernel.org> <1604253261.22363.0.camel@mtkswgap22> <87k0v4u4uq.wl-maz@kernel.org> <87pn4w90hm.fsf@nanos.tec.linutronix.de> <87h7q791j8.fsf@nanos.tec.linutronix.de> <877dr38kt8.fsf@nanos.tec.linutronix.de> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <901c5eb8bbaa3fe53ddc8f65917e48ef@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: tglx@linutronix.de, frank-w@public-files.de, ryder.lee@mediatek.com, linux-mediatek@lists.infradead.org, linux@fw-web.de, linux-kernel@vger.kernel.org, matthias.bgg@gmail.com, linux-pci@vger.kernel.org, bhelgaas@google.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-kernel@vger.kernel.org On 2020-11-02 22:18, Thomas Gleixner wrote: > On Mon, Nov 02 2020 at 17:16, Thomas Gleixner wrote: >> On Mon, Nov 02 2020 at 11:30, Marc Zyngier wrote: >>> --- a/drivers/pci/probe.c >>> +++ b/drivers/pci/probe.c >>> @@ -871,6 +871,8 @@ static void pci_set_bus_msi_domain(struct pci_bus >>> *bus) >>> d = pci_host_bridge_msi_domain(b); >>> >>> dev_set_msi_domain(&bus->dev, d); >>> + if (!d) >>> + bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; >> >> Hrm, that might break legacy setups (no irqdomain support). I'd rather >> prefer to explicitly tell the pci core at host registration time. > > s/might break/ breaks / Just validated :) For my own edification, can you point me to the failing case? > So we really need some other solution and removing the warning is not > an > option. If MSI is enabled then we want to get a warning when a PCI > device has no MSI domain associated. Explicitly expressing the PCIE > brigde misfeature of not supporting MSI is way better than silently > returning an error code which is swallowed anyway. I don't disagree here, though the PCI_MSI_ARCH_FALLBACKS mechanism makes it more difficult to establish. > Whatever the preferred way is via flags at host probe time or flagging > it post probe I don't care much as long as it is consistent. Host probe time is going to require some changes in the core PCI api, as everything that checks for a MSI domain is based on the pci_bus structure, which is only allocated much later. I'll have a think. M. -- Jazz is not dead. It just smells funny...