From: Li Zhang Date: Tue, 13 Aug 2013 18:42:58 +0000 (+0000) Subject: e1000e: Avoid kernel crash during shutdown X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e8c254c5feb92c5b9a6950bc7351e2b1b7b09b93;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git e1000e: Avoid kernel crash during shutdown While doing shutdown on the PCI device, the corresponding callback function e1000e_shutdown() is trying to clear those correctable errors on the upstream P2P bridge. Unfortunately, we don't have the upstream P2P bridge under some cases (e.g. PCI-passthrou for KVM on Power). That leads to kernel crash eventually. The patch adds one more check on that to avoid kernel crash. Signed-off-by: Li Zhang Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 59c0c5413797..e87e9b01f404 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5999,11 +5999,18 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool runtime) * correctable error when the MAC transitions from D0 to D3. To * prevent this we need to mask off the correctable errors on the * downstream port of the pci-e switch. + * + * We don't have the associated upstream bridge while assigning + * the PCI device into guest. For example, the KVM on power is + * one of the cases. */ if (adapter->flags & FLAG_IS_QUAD_PORT) { struct pci_dev *us_dev = pdev->bus->self; u16 devctl; + if (!us_dev) + return 0; + pcie_capability_read_word(us_dev, PCI_EXP_DEVCTL, &devctl); pcie_capability_write_word(us_dev, PCI_EXP_DEVCTL, (devctl & ~PCI_EXP_DEVCTL_CERE));