Messages in this thread Patch in this message | | | Subject | [PATCH bugfix 3.9] PCI: Don't try to disable Bus Master on disconnected PCI devices | From | Konstantin Khlebnikov <> | Date | Thu, 14 Mar 2013 18:49:37 +0400 |
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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: ->shutdown() callback might switch device to deep sleep state. PCI config space no longer available after that.
Link: https://lkml.org/lkml/2013/3/12/529 Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reported-and-Tested-by: Vivek Goyal <vgoyal@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> --- 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
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