On Fri, Sep 14, 2018 at 11:31:34AM +0300, Mika Westerberg wrote:
> Commit baecc470d5fd ("PCI / PM: Skip bridges in pci_enable_wake()")
> changed pci_enable_wake() so that all bridges are skipped when wakeup is
> enabled (or disabled) with the reasoning that bridges can only signal
> wakeup on behalf of their subordinate devices.
>
> However, there are bridges that can signal wakeup itself. For example
> PCIe downstream and root ports supporting hotplug may signal wakeup upon
> hotplug event.
>
> For this reason change pci_enable_wake() so that it skips all bridges
> except those that we power manage (->bridge_d3 is set). Those are the
> ones that can go into low power states and may need to signal wakeup.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Applied to pci/enumeration for v4.20, thanks!
> ---
> Resending this because for some reason it did not hit the mailing lists.
> Added tag from Rafael as well.
>
> drivers/pci/pci.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 29ff9619b5fa..1af6f1887986 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2133,10 +2133,13 @@ static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable
> int ret = 0;
>
> /*
> - * Bridges can only signal wakeup on behalf of subordinate devices,
> - * but that is set up elsewhere, so skip them.
> + * Bridges that are not power-manageable directly only signal
> + * wakeup on behalf of subordinate devices which is set up
> + * elsewhere, so skip them. However, bridges that are
> + * power-manageable may signal wakeup for themselves (for example,
> + * on a hotplug event) and they need to be covered here.
> */
> - if (pci_has_subordinate(dev))
> + if (!pci_power_manageable(dev))
> return 0;
>
> /* Don't do the same thing twice in a row for one device. */
> --
> 2.18.0
>
