The current reset process saves the device's config space state before reset and restores it afterward. However errors may occur unexpectedly and it may then be impossible to save config space because the device may be inaccessible (e.g. DPC) or config space may be corrupted. This results in saving corrupted values that get written back to the device during state restoration.
With a reset we want to recover/restore the device into a functional state. So avoid saving the state of the config space when the device config space is inaccessible.
Signed-off-by: Farhan Ali alifm@linux.ibm.com --- drivers/pci/pci.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c105e285cff8..74d21c97654d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4960,6 +4960,7 @@ EXPORT_SYMBOL_GPL(pci_dev_unlock);
static void pci_dev_save_and_disable(struct pci_dev *dev) { + u32 val; const struct pci_error_handlers *err_handler = dev->driver ? dev->driver->err_handler : NULL;
@@ -4980,6 +4981,12 @@ static void pci_dev_save_and_disable(struct pci_dev *dev) */ pci_set_power_state(dev, PCI_D0);
+ pci_read_config_dword(dev, PCI_COMMAND, &val); + if (PCI_POSSIBLE_ERROR(val)) { + pci_warn(dev, "Device config space inaccessible\n"); + return; + } + pci_save_state(dev); /* * Disable the device by clearing the Command register, except for