[PATCH] USB: core: Enable root_hub's remote wakeup for wakeup sources

[Huacai Chen]

Now we only enable the remote wakeup function for the USB wakeup source
itself at usb_port_suspend(). But on pre-XHCI controllers this is not
enough to enable the S3 wakeup function for USB keyboards, so we also
enable the root_hub's remote wakeup (and disable it on error). Frankly
this is unnecessary for XHCI, but enable it unconditionally make code
simple and seems harmless.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
 drivers/usb/core/hub.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c3f839637cb5..efd6374ccd1d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3480,6 +3480,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 			if (PMSG_IS_AUTO(msg))
 				goto err_wakeup;
 		}
+		usb_enable_remote_wakeup(udev->bus->root_hub);
 	}
 
 	/* disable USB2 hardware LPM */
@@ -3543,8 +3544,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 		/* Try to enable USB2 hardware LPM again */
 		usb_enable_usb2_hardware_lpm(udev);
 
-		if (udev->do_remote_wakeup)
+		if (udev->do_remote_wakeup) {
 			(void) usb_disable_remote_wakeup(udev);
+			(void) usb_disable_remote_wakeup(udev->bus->root_hub);
+		}
  err_wakeup:
 
 		/* System sleep transitions should never fail */
-- 
2.47.1