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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 3CCDDC31E46 for ; Wed, 12 Jun 2019 18:43:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 182B120896 for ; Wed, 12 Jun 2019 18:43:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726656AbfFLSnk (ORCPT ); Wed, 12 Jun 2019 14:43:40 -0400 Received: from mga05.intel.com ([192.55.52.43]:39216 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbfFLSnk (ORCPT ); Wed, 12 Jun 2019 14:43:40 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Jun 2019 11:43:40 -0700 X-ExtLoop1: 1 Received: from linux.intel.com ([10.54.29.200]) by fmsmga008.fm.intel.com with ESMTP; 12 Jun 2019 11:43:39 -0700 Received: from [10.54.74.33] (skuppusw-desk.jf.intel.com [10.54.74.33]) by linux.intel.com (Postfix) with ESMTP id D014E5803E4; Wed, 12 Jun 2019 11:43:39 -0700 (PDT) Reply-To: sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v2 1/1] PCI/IOV: Fix incorrect cfg_size for VF > 0 To: Alex Williamson Cc: bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com, mike.campin@intel.com References: <20190612170647.43220-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20190612121910.231368e2@x1.home> From: sathyanarayanan kuppuswamy Organization: Intel Message-ID: <0b21c76e-53f3-c35e-cebf-00719e451b11@linux.intel.com> Date: Wed, 12 Jun 2019 11:41:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190612121910.231368e2@x1.home> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 6/12/19 11:19 AM, Alex Williamson wrote: > On Wed, 12 Jun 2019 10:06:47 -0700 > sathyanarayanan.kuppuswamy@linux.intel.com wrote: > >> From: Kuppuswamy Sathyanarayanan >> >> Commit 975bb8b4dc93 ("PCI/IOV: Use VF0 cached config space size for >> other VFs") calculates and caches the cfg_size for VF0 device before >> initializing the pcie_cap of the device which results in using incorrect >> cfg_size for all VF devices > 0. So set pcie_cap of the device before >> calculating the cfg_size of VF0 device. >> >> Fixes: 975bb8b4dc93 ("PCI/IOV: Use VF0 cached config space size for >> other VFs") >> Cc: Ashok Raj >> Suggested-by: Mike Campin >> Signed-off-by: Kuppuswamy Sathyanarayanan >> --- >> >> Changes since v1: >> * Fixed a typo in commit message. >> >> drivers/pci/iov.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c >> index 3aa115ed3a65..2869011c0e35 100644 >> --- a/drivers/pci/iov.c >> +++ b/drivers/pci/iov.c >> @@ -160,6 +160,7 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id) >> virtfn->device = iov->vf_device; >> virtfn->is_virtfn = 1; >> virtfn->physfn = pci_dev_get(dev); >> + virtfn->pcie_cap = pci_find_capability(virtfn, PCI_CAP_ID_EXP); >> >> if (id == 0) >> pci_read_vf_config_common(virtfn); > Why not re-order until after we've setup pcie_cap? > > https://lore.kernel.org/linux-pci/20190604143617.0a226555@x1.home/T/# pci_read_vf_config_common() also caches values for properties like class, hdr_type, susbsystem_vendor/device. These values are read/used in pci_setup_device(). So if we can use cached values in pci_setup_device(), we don't have to read them from registers twice for each device. > > Thanks, > Alex > -- Sathyanarayanan Kuppuswamy Linux kernel developer