PCI: Don't try to disable Bus Master on disconnected PCI devices From: Konstantin Khlebnikov This is fix for commit 7897e6022761ace7377f0f784fca059da55f5d71 from v3.9-rc1 ("PCI: Disable Bus Master unconditionally in pci_device_shutdown()") in turn that was fix for b566a22c23327f18ce941ffad0ca907e50a53d41 from v3.5-rc1 ("PCI: disable Bus Master on PCI device shutdown") Unfortunately fixing one bug uncovers another: after ->shutdown() device can be already disconnected from the bus and configuration space in no longer available Link: https://lkml.org/lkml/2013/3/12/529 Signed-off-by: Konstantin Khlebnikov Reported-by: Vivek Goyal Cc: Bjorn Helgaas Cc: Rafael J. Wysocki --- drivers/pci/pci-driver.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 1fa1e48..79277fb 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -390,9 +390,10 @@ static void pci_device_shutdown(struct device *dev) /* * Turn off Bus Master bit on the device to tell it to not - * continue to do DMA + * continue to do DMA. Don't touch devices in D3cold or unknown states. */ - pci_clear_master(pci_dev); + if (pci_dev->current_state <= PCI_D3hot) + pci_clear_master(pci_dev); } #ifdef CONFIG_PM