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authorLinus Torvalds <torvalds@linux-foundation.org>2021-06-23 09:40:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-23 09:40:55 -0700
commit7266f2030eb0e17c442aa6cf527263828eed79bd (patch)
tree48dc945416c7b76c9085e720920c10798d3617f4 /drivers
parent8fd2ed1c01dd96396c39dfa203c54705c6b6e03b (diff)
parent4d6035f9bf4ea12776322746a216e856dfe46698 (diff)
Merge tag 'pm-5.13-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki: "Revert a recent PCI power management commit that causes initialization issues to appear on some systems" * tag 'pm-5.13-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "PCI: PM: Do not read power state in pci_enable_device_flags()"
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pci/pci.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b717680377a9..8d4ebe095d0c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1900,11 +1900,21 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
int err;
int i, bars = 0;
- if (atomic_inc_return(&dev->enable_cnt) > 1) {
- pci_update_current_state(dev, dev->current_state);
- return 0; /* already enabled */
+ /*
+ * 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_inc_return(&dev->enable_cnt) > 1)
+ return 0; /* already enabled */
+
bridge = pci_upstream_bridge(dev);
if (bridge)
pci_enable_bridge(bridge);