On Mon, Jun 12, 2017 at 10:53:36PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> The wakeup_prepared PCI device flag is used for preventing subsequent
> changes of PCI device wakeup settings in the same way (e.g. enabling
> device wakeup twice in a row).
>
> However, in some cases PME Enable may be updated by things like PCI
> configuration space restoration in the meantime and it may need to be
> set again even though the rest of the settings need not change, so
> modify __pci_enable_wake() to do that when it is about to return
> early.
>
> Also, it is reasonable to expect that __pci_enable_wake() will always
> clear PME Status when invoked to disable device wakeup, so make it do
> so even if it is going to return early then.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/pci.c | 26 ++++++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> Index: linux-pm/drivers/pci/pci.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.c
> +++ linux-pm/drivers/pci/pci.c
> @@ -1805,6 +1805,23 @@ static void __pci_pme_active(struct pci_
> pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
> }
>
> +static void pci_pme_restore(struct pci_dev *dev)
> +{
> + u16 pmcsr;
> +
> + if (!dev->pme_support)
> + return;
> +
> + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
> + if (dev->wakeup_prepared) {
> + pmcsr |= PCI_PM_CTRL_PME_ENABLE;
> + } else {
> + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
> + pmcsr |= PCI_PM_CTRL_PME_STATUS;
> + }
> + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
> +}
> +
> /**
> * pci_pme_active - enable or disable PCI device's PME# function
> * @dev: PCI device to handle.
> @@ -1899,9 +1916,14 @@ int __pci_enable_wake(struct pci_dev *de
> if (enable && !runtime && !device_may_wakeup(&dev->dev))
> return -EINVAL;
>
> - /* Don't do the same thing twice in a row for one device. */
> - if (!!enable == !!dev->wakeup_prepared)
> + /*
> + * Don't do the same thing twice in a row for one device, but restore
> + * PME Enable in case it has been updated by config space restoration.
> + */
> + if (!!enable == !!dev->wakeup_prepared) {
> + pci_pme_restore(dev);
> return 0;
> + }
>
> /*
> * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
>
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