On Friday, December 27, 2019 10:24:05 AM CET Kai-Heng Feng wrote: > We have a Pericom USB add-on card that has three USB controller > functions 06:00.[0-2], connected to bridge device 05:03.0, which is > connected to another bridge device 04:00.0: > > -[0000:00]-+-00.0 > +-1c.6-[04-06]----00.0-[05-06]----03.0-[06]--+-00.0 > | +-00.1 > | \-00.2 > > When bridge device (05:03.0) and all three USB controller functions > (06:00.[0-2]) are runtime suspended, they don't get woken up by plugging > USB devices into the add-on card. > > This is because the pcieport driver failed to probe on 04:00.0, since > the device supports neither legacy IRQ, MSI nor MSI-X. Because of that, > there's no native PCIe PME can work for devices connected to it. But in that case the PME driver (drivers/pci/pcie/pme.c) should not bind to the port in question, so the "can_wakeup" flag should not be set for the devices under that port. > So let's correctly report runtime wakeup isn't supported when any of > PCIe bridges isn't bound to pcieport driver. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205981 > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > --- > drivers/pci/pci.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 951099279192..ca686cfbd65e 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -2493,6 +2493,18 @@ bool pci_dev_run_wake(struct pci_dev *dev) > if (!pci_pme_capable(dev, pci_target_state(dev, true))) > return false; > > + /* If any upstream PCIe bridge isn't bound to pcieport driver, there's > + * no IRQ for PME. > + */ > + if (pci_is_pcie(dev)) { > + while (bus->parent) { > + if (!bus->self->driver) > + return false; > + > + bus = bus->parent; > + } > + } > + So it looks like device_can_wakeup() returns 'true' for this device, but it should return 'false'. Do you know why the "can_wakeup" flag is set for it? > if (device_can_wakeup(&dev->dev)) > return true; > > Moreover, even if the native PME is not supported, there can be an ACPI GPE (or equivalent) that triggers when WAKE# is asserted by one of the PCIe devices connected to it, so the test added by this patch cannot be used in general.
