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path: root/drivers/pci/pci.c
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Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e98c8104297b..710c8a29be0d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1007,6 +1007,18 @@ static int __pci_enable_device_flags(struct pci_dev *dev,
int err;
int i, bars = 0;
+ /*
+ * Power state could be unknown at this point, either due to a fresh
+ * boot or a device removal call. So get the current power state
+ * so that things like MSI message writing will behave as expected
+ * (e.g. if the device really is in D0 at enable time).
+ */
+ if (dev->pm_cap) {
+ u16 pmcsr;
+ pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
+ dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
+ }
+
if (atomic_add_return(1, &dev->enable_cnt) > 1)
return 0; /* already enabled */