On Tue, May 10, 2022 at 06:46:02AM +0530, Pavan Kondeti wrote:
> On Mon, May 09, 2022 at 10:33:59AM -0400, Alan Stern wrote:
> > On Mon, May 09, 2022 at 07:53:41PM +0530, Pavan Kondeti wrote:
> > > On Mon, May 09, 2022 at 10:08:41AM -0400, Alan Stern wrote:
> > > > BTW, if there's any trouble with getting device_wakeup_path() to work
> > > > the way you want, you could consider instead calling
> > > > usb_wakeup_enabled_descendants() on the root hub. This function returns
> > > > a count of the number of wakeup-enabled USB devices at or below the
> > > > device you pass to it.
> > > >
> > >
> > > This series [1] started with usb_wakeup_enabled_descendants() actually. one
> > > of the problem with this API is that we have to call this on both USB2.0 and
> > > USB3.0 root hubs. Do you think we can have a wrapper function like
> > > usb_hcd_wakeup_enabled_descendants() that accepts hcd as an argument and
> > > internally call usb_wakeup_enabled_descendants() on both root hubs and return
> > > the result.
> >
> > Sure you can. Feel free to write such a function and add it to hcd.c.
> > Ideally it should work for host controllers with any number of root
> > hubs, just adding up the number of wakeup-enabled descendants for all of
> > them.
> >
> Thanks Alan for the suggestion. Does the below diff looks good?
It looks fine, aside from lacking any comments/kerneldoc.
Alan Stern
> Thanks,
> Pavan
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index c9443aa..f707f9b 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2704,6 +2704,19 @@ int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
> }
> EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
>
> +unsigned int usb_hcd_wakeup_enabled_descendants(struct usb_hcd *hcd)
> +{
> + unsigned int nr_wakeup;
> +
> + nr_wakeup = usb_wakeup_enabled_descendants(hcd->self.root_hub);
> +
> + if (hcd->shared_hcd)
> + nr_wakeup += usb_wakeup_enabled_descendants(hcd->shared_hcd->self.root_hub);
> +
> + return nr_wakeup;
> +}
> +EXPORT_SYMBOL_GPL(usb_hcd_wakeup_enabled_descendants);
> +
> int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
> {
> if (!hcd->driver->find_raw_port_number)
> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> index 1886e81..a5d561b 100644
> --- a/include/linux/usb/hcd.h
> +++ b/include/linux/usb/hcd.h
> @@ -474,6 +474,7 @@ extern void usb_remove_hcd(struct usb_hcd *hcd);
> extern int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1);
> int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
> dma_addr_t dma, size_t size);
> +extern unsigned int usb_hcd_wakeup_enabled_descendants(struct usb_hcd *hcd);
>
> struct platform_device;
> extern void usb_hcd_platform_shutdown(struct platform_device *dev);
>
