From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Huang Ying To: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Huang Ying Subject: [RFC 1/3] PCI/PM: Fix kexec for D3cold and bridge suspending Date: Mon, 17 Sep 2012 16:54:34 +0800 Message-Id: <1347872076-5260-2-git-send-email-ying.huang@intel.com> In-Reply-To: <1347872076-5260-1-git-send-email-ying.huang@intel.com> References: <1347872076-5260-1-git-send-email-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: If PCI devices are put into D3cold before kexec, because the configuration registers of PCI devices in D3cold are not accessible. And if PCI bridges are put into low power state before kexec, configuration registers of PCI devices underneath the PCI bridges are not accessible too. These will make some PCI devices can not be scanned after kexec, so resume the PCI devices in D3cold or PCI bridges in low power state before kexec. Signed-off-by: Huang Ying --- drivers/pci/pci-driver.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -421,6 +421,10 @@ static void pci_device_shutdown(struct d struct pci_dev *pci_dev = to_pci_dev(dev); struct pci_driver *drv = pci_dev->driver; + /* Resume bridges and devices in D3cold for kexec to work properly */ + if (pci_dev->current_state == PCI_D3cold || pci_dev->subordinate) + pm_runtime_resume(dev); + if (drv && drv->shutdown) drv->shutdown(pci_dev); pci_msi_shutdown(pci_dev);