[PATCH] PCI: PCIE power management quirk

When changing power states from D0->DX and then from DX->D0, some
Intel PCIE chipsets will cause a device reset to occur.  This will
cause problems for any D State other than D3, since any state
information that the driver will expect to be present coming from
a D1 or D2 state will have been cleared.  This patch addes a
flag to the pci_dev structure to indicate that devices should
not use states D1 or D2, and will set that flag for the affected
chipsets.  This patch also modifies pci_set_power_state() so that
when a device driver tries to set the power state on
a device that is downstream from an affected chipset, or on one
of the affected devices it only allows state changes to or
from D0 & D3.  In addition, this patch allows the delay time
between D3->D0 to be changed via a quirk.  These chipsets also
need additional time to change states beyond the normal 10ms.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9cc842b..08d58fc 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -47,7 +47,7 @@ extern int pci_msi_quirk;
 #else
 #define pci_msi_quirk 0
 #endif
-
+extern unsigned int pci_pm_d3_delay;
 #ifdef CONFIG_PCI_MSI
 void disable_msi_mode(struct pci_dev *dev, int pos, int type);
 void pci_no_msi(void);
@@ -66,7 +66,15 @@ static inline int pci_save_msix_state(struct pci_dev *dev) { return 0; }
 static inline void pci_restore_msi_state(struct pci_dev *dev) {}
 static inline void pci_restore_msix_state(struct pci_dev *dev) {}
 #endif
+static inline int pci_no_d1d2(struct pci_dev *dev)
+{
+	unsigned int parent_dstates = 0;
 
+	if (dev->bus->self)
+		parent_dstates = dev->bus->self->no_d1d2;
+	return (dev->no_d1d2 || parent_dstates);
+
+}
 extern int pcie_mch_quirk;
 extern struct device_attribute pci_dev_attrs[];
 extern struct class_device_attribute class_device_attr_cpuaffinity;