From patchwork Thu Aug 15 02:18:54 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yijing Wang X-Patchwork-Id: 267302 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 4AFC92C020D for ; Thu, 15 Aug 2013 12:19:25 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759988Ab3HOCTY (ORCPT ); Wed, 14 Aug 2013 22:19:24 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:45904 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759785Ab3HOCTY (ORCPT ); Wed, 14 Aug 2013 22:19:24 -0400 Received: from 172.24.2.119 (EHLO szxeml205-edg.china.huawei.com) ([172.24.2.119]) by szxrg03-dlp.huawei.com (MOS 4.4.2a-FCS FastPath queued) with ESMTP id ADE57928; Thu, 15 Aug 2013 10:19:17 +0800 (CST) Received: from SZXEML455-HUB.china.huawei.com (10.82.67.198) by szxeml205-edg.china.huawei.com (172.24.2.58) with Microsoft SMTP Server (TLS) id 14.1.323.7; Thu, 15 Aug 2013 10:19:15 +0800 Received: from localhost (10.135.76.69) by SZXEML455-HUB.china.huawei.com (10.82.67.198) with Microsoft SMTP Server id 14.1.323.7; Thu, 15 Aug 2013 10:19:07 +0800 From: Yijing Wang To: Bjorn Helgaas CC: Jon Mason , , Hanjun Guo , , Yijing Wang , Subject: [PATCH v5 1/2] PCI: fix the only slot identification in pcie_find_smpss() Date: Thu, 15 Aug 2013 10:18:54 +0800 Message-ID: <1376533135-36708-2-git-send-email-wangyijing@huawei.com> X-Mailer: git-send-email 1.7.11.msysgit.1 In-Reply-To: <1376533135-36708-1-git-send-email-wangyijing@huawei.com> References: <1376533135-36708-1-git-send-email-wangyijing@huawei.com> 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 We use list_is_singular() to identify the slot whether is only slot directly connected to the root port in pcie_find_smpss(). It's not correct, if we have only slot connected to root port, and this slot has two function devices. list_is_singular() return false. This patch introduces pci_only_one_slot() to fix this issue. In addition, we should pass subordinate bus devices list to list_is_singular(), not its parent bus devices list. -+-[0000:40]-+-00.0-[0000:41]-- ...................... | +-07.0-[0000:46]--+-00.0 Intel Corporation 82576 Gigabit Network Connection | | \-00.1 Intel Corporation 82576 Gigabit Network Connection MPS configure after boot up, with boot command "pci=pcie_bus_safe" linux-ha2:~ # lspci -vvv -s 40:07.0 40:07.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 7 (rev 22) (prog-if 00 [Normal decode]) ............... Capabilities: [90] Express (v2) Root Port (Slot+), MSI 00 DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag+ RBE+ FLReset- DevCtl: Report errors: Correctable+ Non-Fatal+ Fatal+ Unsupported+ RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 256 bytes, MaxReadReq 128 bytes linux-ha2:~ # lspci -vvv -s 46:00.0 46:00.0 Ethernet controller: Intel Corporation 82576 Gigabit Network Connection (rev 01) ............... Capabilities: [a0] Express (v2) Endpoint, MSI 00 DevCap: MaxPayload 512 bytes, PhantFunc 0, Latency L0s <512ns, L1 <64us ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ DevCtl: Report errors: Correctable+ Non-Fatal+ Fatal+ Unsupported+ RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset- MaxPayload 256 bytes, MaxReadReq 512 bytes linux-ha2:/sys/bus/pci/slots/7 # echo 0 > power ------>power off slot linux-ha2:/sys/bus/pci/slots/7 # echo 1 > power ------>power on slot linux-ha2:/sys/bus/pci/slots/7 # dmesg ................ pcieport 0000:40:07.0: PCI-E Max Payload Size set to 128/ 256 (was 256), Max Read Rq 128 pci 0000:46:00.0: PCI-E Max Payload Size set to 128/ 512 (was 128), Max Read Rq 512 pci 0000:46:00.1: PCI-E Max Payload Size set to 128/ 512 (was 128), Max Read Rq 512 pcieport 0000:40:07.0: PCI-E Max Payload Size set to 128/ 256 (was 128), Max Read Rq 128 pci 0000:46:00.0: PCI-E Max Payload Size set to 128/ 512 (was 128), Max Read Rq 512 pci 0000:46:00.1: PCI-E Max Payload Size set to 128/ 512 (was 128), Max Read Rq 512 ..... Because 46:00.0 and 46:00.1 function devices are directly connected to root port 40:07.0. After slot hot plug, root port mps is 256, slot fun devices(46:00.0/1) mps is 128. We should both change root port and slot mps to 256, but now kernel change mps to 128. After applied this patch, dmesg after hot plug: .............. pcieport 0000:40:07.0: PCI-E Max Payload Size set to 256/ 256 (was 256), Max Read Rq 128 pci 0000:46:00.0: PCI-E Max Payload Size set to 256/ 512 (was 128), Max Read Rq 512 pci 0000:46:00.1: PCI-E Max Payload Size set to 256/ 512 (was 128), Max Read Rq 512 pcieport 0000:40:07.0: PCI-E Max Payload Size set to 256/ 256 (was 256), Max Read Rq 128 pci 0000:46:00.0: PCI-E Max Payload Size set to 256/ 512 (was 256), Max Read Rq 512 pci 0000:46:00.1: PCI-E Max Payload Size set to 256/ 512 (was 256), Max Read Rq 512 Acked-by: Jon Mason Signed-off-by: Yijing Wang Cc: Jon Mason Cc: stable@vger.kernel.org # 3.4+ --- drivers/pci/probe.c | 20 +++++++++++++++++++- 1 files changed, 19 insertions(+), 1 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index cf57fe7..0699ec0 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1484,6 +1484,24 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) return nr; } +static bool pci_only_one_slot(struct pci_bus *pbus) +{ + u8 device; + struct pci_dev *pdev; + + if (!pbus || list_empty(&pbus->devices)) + return false; + + pdev = list_entry(pbus->devices.next, + struct pci_dev, bus_list); + device = PCI_SLOT(pdev->devfn); + list_for_each_entry(pdev, &pbus->devices, bus_list) + if (PCI_SLOT(pdev->devfn) != device) + return false; + + return true; +} + static int pcie_find_smpss(struct pci_dev *dev, void *data) { u8 *smpss = data; @@ -1506,7 +1524,7 @@ static int pcie_find_smpss(struct pci_dev *dev, void *data) * common case), then this is not an issue and MPS discovery * will occur as normal. */ - if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) || + if (dev->is_hotplug_bridge && (!pci_only_one_slot(dev->subordinate) || (dev->bus->self && pci_pcie_type(dev->bus->self) != PCI_EXP_TYPE_ROOT_PORT))) *smpss = 0;