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()"
This commit is contained in:
Linus Torvalds
2021-06-23 09:40:55 -07:00

View File

@@ -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);