usbcore: set lpm_capable field for LPM capable root hubs

This patch sets the lpm_capable field for root hubs with LPM capabilities.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: Martin MOKREJS <mmokrejs@gmail.com>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 8 insertions, 1 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index ab54999da2bf..9795a21bc612 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1033,6 +1033,7 @@ static int register_root_hub(struct usb_hcd *hcd)
                                         dev_name(&usb_dev->dev), retval);
                         return retval;
                 }
+                usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
         }
 
         retval = usb_new_device (usb_dev);
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index dde4c83516a1..52a1de99c6f2 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -135,7 +135,7 @@ struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
         return usb_get_intfdata(hdev->actconfig->interface[0]);
 }
 
-static int usb_device_supports_lpm(struct usb_device *udev)
+int usb_device_supports_lpm(struct usb_device *udev)
 {
         /* USB 2.1 (and greater) devices indicate LPM support through
          * their USB 2.0 Extended Capabilities BOS descriptor.
@@ -156,6 +156,11 @@ static int usb_device_supports_lpm(struct usb_device *udev)
                                 "Power management will be impacted.\n");
                 return 0;
         }
+
+        /* udev is root hub */
+        if (!udev->parent)
+                return 1;
+
         if (udev->parent->lpm_capable)
                 return 1;
 
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 823857767a16..c49383669cd8 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -35,6 +35,7 @@ extern int usb_get_device_descriptor(struct usb_device *dev,
                 unsigned int size);
 extern int usb_get_bos_descriptor(struct usb_device *dev);
 extern void usb_release_bos_descriptor(struct usb_device *dev);
+extern int usb_device_supports_lpm(struct usb_device *udev);
 extern char *usb_cache_string(struct usb_device *udev, int index);
 extern int usb_set_configuration(struct usb_device *dev, int configuration);
 extern int usb_choose_configuration(struct usb_device *udev);