Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755971Ab3GKJok (ORCPT ); Thu, 11 Jul 2013 05:44:40 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:50292 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755882Ab3GKJoh (ORCPT ); Thu, 11 Jul 2013 05:44:37 -0400 From: Yijing Wang To: Bjorn Helgaas CC: , , Rafael , Hanjun Guo , , Yijing Wang , Paul Bolle , Oliver Neukum , Gu Zheng Subject: [PATCH -v2 3/3] PCI,pciehp: use PCIe DSN to identify device change during suspend Date: Thu, 11 Jul 2013 17:43:45 +0800 Message-ID: <1373535825-49972-4-git-send-email-wangyijing@huawei.com> X-Mailer: git-send-email 1.7.11.msysgit.1 In-Reply-To: <1373535825-49972-1-git-send-email-wangyijing@huawei.com> References: <1373535825-49972-1-git-send-email-wangyijing@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.135.76.69] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2695 Lines: 94 If device was removed from slot and reinsert a new device during suspend, pciehp can not identify the physical device change now. So the old driver .resume() method will be called for the new device, this is bad. If device support device serial number capability, we can identify this by DSN. So the reasonable way is first remove the old device, then enable the new device. Signed-off-by: Yijing Wang Cc: Paul Bolle Cc: "Rafael J. Wysocki" Cc: Oliver Neukum Cc: Gu Zheng Cc: linux-pci@vger.kernel.org --- drivers/pci/hotplug/pciehp_core.c | 45 +++++++++++++++++++++++++++++++++++++ 1 files changed, 45 insertions(+), 0 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index 1542735..f2eb214 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -296,11 +296,38 @@ static int pciehp_suspend (struct pcie_device *dev) return 0; } +/* + * check the func 0 device serial number is changed, + * if device does not support device serial number, + * return false. + */ +static bool device_serial_number_changed(struct pci_bus *pbus) +{ + u64 old_dsn, new_dsn; + struct pci_dev *pdev; + + pdev = pci_get_slot(pbus, PCI_DEVFN(0, 0)); + if (!pdev) + return false; + + old_dsn = pdev->sn; + + /* get func 0 device serial number */ + new_dsn = pci_device_serial_number(pdev); + pci_dev_put(pdev); + + if (old_dsn != new_dsn) + return true; + + return false; +} + static int pciehp_resume (struct pcie_device *dev) { struct controller *ctrl; struct slot *slot; struct pci_bus *pbus = dev->port->subordinate; + int retval = 0; u8 status; ctrl = get_service_data(dev); @@ -315,6 +342,24 @@ static int pciehp_resume (struct pcie_device *dev) if (status) { if (list_empty(&pbus->devices)) pciehp_enable_slot(slot); + + if (device_serial_number_changed(pbus)) { + /* + * first power off slot, avoid the old driver + * .remove() method touch the new hardware + */ + if (POWER_CTRL(ctrl)) { + retval = pciehp_power_off_slot(slot); + if (retval) { + ctrl_err(ctrl, + "Issue of Slot Disable command failed\n"); + return 0; + } + msleep(1000); + pciehp_unconfigure_device(slot); + pciehp_enable_slot(slot); + } + } } else if (!list_empty(&pbus->devices)) pciehp_disable_slot(slot); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/