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?
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);
