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| author | Khalid Aziz <khalid.aziz@hp.com> | 2012-04-27 13:00:33 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2012-05-04 11:07:18 -0600 |
| commit | b566a22c23327f18ce941ffad0ca907e50a53d41 (patch) | |
| tree | ce675ff2f56a88778ea051f779868ffb9d746160 /drivers/pci | |
| parent | df558de16c8a90e44ffb405e9224980b15158c93 (diff) | |
| download | op-kernel-dev-b566a22c23327f18ce941ffad0ca907e50a53d41.zip op-kernel-dev-b566a22c23327f18ce941ffad0ca907e50a53d41.tar.gz | |
PCI: disable Bus Master on PCI device shutdown
Disable Bus Master bit on the device in pci_device_shutdown() to ensure PCI
devices do not continue to DMA data after shutdown. This can cause memory
corruption in case of a kexec where the current kernel shuts down and
transfers control to a new kernel while a PCI device continues to DMA to
memory that does not belong to it any more in the new kernel.
I have tested this code on two laptops, two workstations and a 16-socket
server. kexec worked correctly on all of them.
Signed-off-by: Khalid Aziz <khalid.aziz@hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci-driver.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 6b54b23..bf0cee6 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -421,6 +421,12 @@ static void pci_device_shutdown(struct device *dev) pci_msix_shutdown(pci_dev); /* + * Turn off Bus Master bit on the device to tell it to not + * continue to do DMA + */ + pci_disable_device(pci_dev); + + /* * Devices may be enabled to wake up by runtime PM, but they need not * be supposed to wake up the system from its "power off" state (e.g. * ACPI S5). Therefore disable wakeup for all devices that aren't |
