On Fri, 1 Jun 2018, Anshuman Gupta wrote:
> On Thu, May 31, 2018 at 03:49:46PM -0400, Alan Stern wrote:
> > On Thu, 31 May 2018, Anshuman Gupta wrote:
> >
> > > > + resuming_ports = hcd->driver->get_resuming_ports(hcd);
> > > > + for (i = 0; i < hdev->maxchild; ++i) {
> > > > + if (test_bit(i, &resuming_ports)) {
> > > > + struct usb_port *port_dev = hub->ports[i];
> > > > +
> > > > + pm_wakeup_event(&port_dev->dev, 0);
> > > port_dev does not have a wakeup source, there will not any wakeup_count increment
> > > for port_dev, usb_dev for a particular port has wakeup source associated with it,
> > > so using port_dev->child usb_dev instead of usb_port device.
> >
> > Okay. However, there might not be a child usb_dev below the port. For
> > example, a wakeup signal could happen as a result of the user plugging
> > in a new device.
> Wake on connect/disconnect wakeup sources are basiclly root hub devices i.e. usb_dev
> usb1 and usb2 "/sys/bus/usb/devices/usb1/power/wakeup"
That's right; a newly plugged-in device won't send a wakeup signal.
All right, forget I made that comment.
> > In any case, when the system wakes up because of a signal received by a
> > USB host controller, there should be a wakeup event associated with the
> > host controller. Don't you get those events?
> There are no wakeup attributes for usb_port devices
> Ex. "cat /sys/bus/usb/devices/1-0\:1.0/usb1-port5/power/"
> usb_port devcies are not wakeup capable.
> I think wake on connect pm_wakeup_events should be handle by root hub
> usb_dev.
You misunderstand. I'm talking about host controller devices like
/sys/bus/pci/devices/0000:00:14.0. Not usb_port devices.
These host controller devices are wakeup capable, and they are the
devices responsible for actually waking up the system when a wakeup
request is received over USB. You should be getting wakeup events from
the controller.
> > Alan Stern
> >
> > PS: Do you have a wakeup-capable USB-3 device? I'm not sure that the
> > patch will work the way you want for USB-3 devices.
> >
> I do not have any USB-3 wake capable device to test, but will try with
> USB type-c mouse,if that will be a USB 3 device,
> I think USB 3.0 pm_wakeup_event will be handle by
> https://elixir.bootlin.com/linux/latest/source/drivers/usb/core/hub.c#L66
A mouse won't be USB-3, not even a mouse with a type-C connector.
Alan Stern
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