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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 3078CC11F68 for ; Fri, 2 Jul 2021 15:55:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F055E61423 for ; Fri, 2 Jul 2021 15:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230304AbhGBP5y (ORCPT ); Fri, 2 Jul 2021 11:57:54 -0400 Received: from maynard.decadent.org.uk ([95.217.213.242]:50992 "EHLO maynard.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229807AbhGBP5x (ORCPT ); Fri, 2 Jul 2021 11:57:53 -0400 X-Greylist: delayed 926 seconds by postgrey-1.27 at vger.kernel.org; Fri, 02 Jul 2021 11:57:53 EDT Received: from 168.7-181-91.adsl-dyn.isp.belgacom.be ([91.181.7.168] helo=deadeye) by maynard with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lzLGk-0004Ip-Ng; Fri, 02 Jul 2021 17:39:54 +0200 Received: from ben by deadeye with local (Exim 4.94.2) (envelope-from ) id 1lzLGf-001UmD-PL; Fri, 02 Jul 2021 17:39:49 +0200 Message-ID: <237a49d8a113f44b55e537f6f2f99b7db9d97485.camel@decadent.org.uk> Subject: Re: [PATCH 1/2] PCI: Call MPS fixup quirks early From: Ben Hutchings To: Bjorn Helgaas , Marek =?ISO-8859-1?Q?Beh=FAn?= Cc: linux-pci@vger.kernel.org, Pali =?ISO-8859-1?Q?Roh=E1r?= , =?ISO-8859-1?Q?R=F6tti?= , Zachary Zhang , Edward Cree , Martin Habets , Keith Busch Date: Fri, 02 Jul 2021 17:39:43 +0200 In-Reply-To: <20210701152512.GA55520@bjorn-Precision-5520> References: <20210701152512.GA55520@bjorn-Precision-5520> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-bgrN+a4HOYy97Q+kIw+b" User-Agent: Evolution 3.38.3-1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 91.181.7.168 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on maynard); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org --=-bgrN+a4HOYy97Q+kIw+b Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2021-07-01 at 10:25 -0500, Bjorn Helgaas wrote: [...] > After 27d868b5e6cfa, pci_configure_device() did actually call > pcie_set_mps(), which updates the Device Control register (possibly > restricted by dev->pcie_mpss, which is set by this quirk). >=20 > The fixup_mpss_256() quirk was added in 2011 by a94d072b2023 ("PCI: > Add quirk for known incorrect MPSS"). Interesting that 27d868b5e6cfa > was merged in 2015 but apparently nobody noticed until now. I guess > those Solarflare devices aren't widely used? [...] The key thing is that this quirk was working around an issue with legacy interrupts, while the sfc and sfc-falcon drivers have always preferred to use MSIs if available. (But I also don't think many SFC4000-based NICs were sold, and they were EOL'd about 10 years ago.) Ben. >=20 --=20 Ben Hutchings [W]e found...that it wasn't as easy to get programs right as we had thought. I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs. - Maurice Wilkes, 1949 --=-bgrN+a4HOYy97Q+kIw+b Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEErCspvTSmr92z9o8157/I7JWGEQkFAmDfMz8ACgkQ57/I7JWG EQkWCw//XXi1mIbkVday8wdafklHJvcU/n6+vMrHa1opAGCRiILGUfuuw1GLmrti 7mttUcfPOpOtMYz9n0FaOxjzEYv0KF7Pl7re5EdZLT6dJnqa0u2p85EbnyiOEKVL 5ngFpvNNxLla692wUWfH6Dcp2D3fybQJo0TVDef4GSsNuAj6MbQGHV1egCheB+eo qRcHJis4LYhjzSiWUW9O0SJe1CwstxntnGCnjXl3o1H+VTJLrzk7Fc3StSWfvMgv qCLkYynO/zOkMGJw/ZkqWKMd56vIrUFNlQ4cN4cThOMPMKHGmlVD6l74z5csgnfr DaRvFIKDLjciAIjXZ/nr8Mp8trSuq4ULJxDDAVO0lnUHA/lz4PzsVZjctctVNtY9 cj1kGSC6Zmw78SXIjXEbhoUCt0ugs0lnWiQjk4/3+cNId7xtn9WMwyxDTJWLhM1l LGpNCDsg1LylaHsapKTAw71NUIQ1ZJjjPNNx+dyaiim3Z9QhiwzMAem7eNLqvE98 CYkONtsLekxVNuWs3GVI2XYoi8j5/rcWojnESfrb01lLW6ETRcErJA6PTzFDVDlS 9yxEj4anhmcgX+Z7dHdjRXjb6FE1z3tQIM3pe+DtCKg1TkgmxDp7MDj/SrmzQ6Ub 11VmwUxzZJUe/CuySK8cgxZbNI6hZqSpmEWmCjZ+qxG8uv0zJO0= =rwnt -----END PGP SIGNATURE----- --=-bgrN+a4HOYy97Q+kIw+b--