diff options
| author | Khalid Aziz <khalid.aziz@oracle.com> | 2013-11-27 15:19:25 -0700 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2013-12-07 14:20:28 -0700 |
| commit | 4fc9bbf98fd66f879e628d8537ba7c240be2b58e (patch) | |
| tree | 09cdc49f0f145f7af3380c7896fa539d4192ca1d /drivers/pci | |
| parent | f407dae76040c9529c2c83b1488dda4ffc54522c (diff) | |
PCI: Disable Bus Master only on kexec reboot
Add a flag to tell the PCI subsystem that kernel is shutting down in
preparation to kexec a kernel. Add code in PCI subsystem to use this flag
to clear Bus Master bit on PCI devices only in case of kexec reboot.
This fixes a power-off problem on Acer Aspire V5-573G and likely other
machines and avoids any other issues caused by clearing Bus Master bit on
PCI devices in normal shutdown path. The problem was introduced by
b566a22c2332 ("PCI: disable Bus Master on PCI device shutdown").
This patch is based on discussion at
http://marc.info/?l=linux-pci&m=138425645204355&w=2
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861
Reported-by: Chang Liu <cl91tp@gmail.com>
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: stable@vger.kernel.org # v3.5+
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci-driver.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 7edd5c307446..25f0bc659164 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -19,6 +19,7 @@ #include <linux/cpu.h> #include <linux/pm_runtime.h> #include <linux/suspend.h> +#include <linux/kexec.h> #include "pci.h" struct pci_dynid { @@ -415,12 +416,17 @@ static void pci_device_shutdown(struct device *dev) pci_msi_shutdown(pci_dev); pci_msix_shutdown(pci_dev); +#ifdef CONFIG_KEXEC /* - * Turn off Bus Master bit on the device to tell it to not - * continue to do DMA. Don't touch devices in D3cold or unknown states. + * If this is a kexec reboot, turn off Bus Master bit on the + * device to tell it to not continue to do DMA. Don't touch + * devices in D3cold or unknown states. + * If it is not a kexec reboot, firmware will hit the PCI + * devices with big hammer and stop their DMA any way. */ - if (pci_dev->current_state <= PCI_D3hot) + if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) pci_clear_master(pci_dev); +#endif } #ifdef CONFIG_PM |