From patchwork Thu Jan 24 02:58:08 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yijing Wang X-Patchwork-Id: 215105 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 6E6392C0082 for ; Thu, 24 Jan 2013 13:59:03 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753209Ab3AXC6u (ORCPT ); Wed, 23 Jan 2013 21:58:50 -0500 Received: from szxga01-in.huawei.com ([119.145.14.64]:4041 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752944Ab3AXC6t (ORCPT ); Wed, 23 Jan 2013 21:58:49 -0500 Received: from 172.24.2.119 (EHLO szxeml205-edg.china.huawei.com) ([172.24.2.119]) by szxrg01-dlp.huawei.com (MOS 4.3.4-GA FastPath queued) with ESMTP id AWP80341; Thu, 24 Jan 2013 10:58:44 +0800 (CST) Received: from SZXEML402-HUB.china.huawei.com (10.82.67.32) by szxeml205-edg.china.huawei.com (172.24.2.58) with Microsoft SMTP Server (TLS) id 14.1.323.7; Thu, 24 Jan 2013 10:58:38 +0800 Received: from localhost (10.135.76.69) by szxeml402-hub.china.huawei.com (10.82.67.32) with Microsoft SMTP Server id 14.1.323.7; Thu, 24 Jan 2013 10:58:33 +0800 From: Yijing Wang To: Rob Landley , Bjorn Helgaas CC: , , , Andrew Murray , Joe Lawrence , Randy Dunlap , Hanjun Guo , , Yijing Wang Subject: [PATCH v2] PCI: Document PCIE BUS MPS parameters Date: Thu, 24 Jan 2013 10:58:08 +0800 Message-ID: <1358996288-31200-1-git-send-email-wangyijing@huawei.com> X-Mailer: git-send-email 1.7.11.msysgit.1 MIME-Version: 1.0 X-Originating-IP: [10.135.76.69] X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org v0->v1: Update MPS parameters as non-arch and add MRRS description into pcie_bus_perf parameter suggested by Andrew Murray. v1->v2: Update some semantic problems and add MPS and MRRS explanation suggested by Joe Lawrence and Randy Dunlap. Document PCIE BUS MPS parameters pcie_bus_tune_off, pcie_bus_safe, pcie_bus_peer2peer, pcie_bus_perf into Documentation/kernel-parameters.txt. These parameters were introduced by Jon Mason at commit 5f39e6705 and commit b03e7495a8. Signed-off-by: Yijing Wang --- Documentation/kernel-parameters.txt | 16 ++++++++++++++++ 1 files changed, 16 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 363e348..0bb279f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2227,6 +2227,22 @@ bytes respectively. Such letter suffixes can also be entirely omitted. This sorting is done to get a device order compatible with older (<= 2.4) kernels. nobfsort Don't sort PCI devices into breadth-first order. + pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) + turning and using the BIOS-configured MPS defaults. + pcie_bus_safe Use the smallest common denominator MPS + of the entire tree below a root complex for every + device on that fabric. Can avoid inconsistent MPS + problem caused by hotplug. + pcie_bus_perf Configure pcie device MPS to the largest + allowable MPS based on its parent bus. Also set + MRRS (Max Read Request Size) to the largest supported + value (no larger than the MPS that the device or bus + can support) for Max performance. + pcie_bus_peer2peer Make the system-wide MPS the smallest + possible value (128B). This configuration could prevent + peer to peer DMA transmission from working by having + the MPS on one root port different than the MPS on + another. cbiosize=nn[KMG] The fixed amount of bus space which is reserved for the CardBus bridge's IO window. The default value is 256 bytes.