Re: [PATCH v2 2/3] usb: xhci: implement device_suspend/device_resume entries

[Lu, Baolu]

On 05/06/2015 10:30 PM, Alan Stern wrote:
> On Wed, 6 May 2015, Lu Baolu wrote:
>
> > This patch implements device_suspend/device_resume entries for xHC driver.
> > device_suspend will be called when a USB device is about to suspend. It
> > will issue a stop endpoint command for each endpoint in this device. The
> > Suspend(SP) bit in the command TRB will set which will give xHC a hint
> > about the suspend. device_resume will be called when a USB device is just
> > resumed. It will ring doorbells of all endpoint unconditionally. XHC may
> > use these suspend/resume hints to optimize its operation.
> >
> > Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ...
>
> >   #else /* CONFIG_PM */
> >   
> >   int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
> > @@ -4704,6 +4728,16 @@ int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd,
> >   {
> >   	return 0;
> >   }
> > +
> > +void xhci_device_suspend(struct usb_hcd *hcd,
> > +			struct usb_device *udev, pm_message_t msg)
> > +{
> > +}
> > +
> > +void xhci_device_resume(struct usb_hcd *hcd,
> > +			struct usb_device *udev, pm_message_t msg)
> > +{
> > +}
> You don't need to have empty functions.  Just do this:
>
> #define xhci_device_suspend	NULL
> #define xhci_device_resume	NULL
>
> in the appropriate place, when CONFIG_PM is not enabled.

Yes, I agree. I will change it.

> Alan Stern

Thank you,
Baolu

>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/