USB: Increment wakeup count on remote wakeup.

On chromebooks we depend on wakeup count to identify the wakeup source.
But currently USB devices do not increment the wakeup count when they
trigger the remote wake. This patch addresses the same.

Resume condition is reported differently on USB 2.0 and USB 3.0 devices.

On USB 2.0 devices, a wake capable device, if wake enabled, drives
resume signal to indicate a remote wake (USB 2.0 spec section 7.1.7.7).
The upstream facing port then sets C_PORT_SUSPEND bit and reports a
port change event (USB 2.0 spec section 11.24.2.7.2.3). Thus if a port
has resumed before driving the resume signal from the host and
C_PORT_SUSPEND is set, then the device attached to the given port might
be the reason for the last system wakeup. Increment the wakeup count for
the same.

On USB 3.0 devices, a function may signal that it wants to exit from device
suspend by sending a Function Wake Device Notification to the host (USB3.0
spec section 8.5.6.4) Thus on receiving the Function Wake, increment the
wakeup count.

Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 777036ae63674af94e845a78e0cf75e607f8ba68..00bb8417050fff86562f4e7894eecc79a5be12a8 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2377,6 +2377,7 @@ void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
 
        spin_lock_irqsave (&hcd_root_hub_lock, flags);
        if (hcd->rh_registered) {
+               pm_wakeup_event(&hcd->self.root_hub->dev, 0);
                set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
                queue_work(pm_wq, &hcd->wakeup_work);
        }

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f6ea16e9f6bb975a09e296f2493a5a687828d920..aa9968d90a48c301e6af566d00a20139397e1742 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -653,12 +653,17 @@ void usb_wakeup_notification(struct usb_device *hdev,
                unsigned int portnum)
 {
        struct usb_hub *hub;
+       struct usb_port *port_dev;
 
        if (!hdev)
                return;
 
        hub = usb_hub_to_struct_hub(hdev);
        if (hub) {
+               port_dev = hub->ports[portnum - 1];
+               if (port_dev && port_dev->child)
+                       pm_wakeup_event(&port_dev->child->dev, 0);
+
                set_bit(portnum, hub->wakeup_bits);
                kick_hub_wq(hub);
        }
@@ -3434,8 +3439,11 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 
        /* Skip the initial Clear-Suspend step for a remote wakeup */
        status = hub_port_status(hub, port1, &portstatus, &portchange);
-       if (status == 0 && !port_is_suspended(hub, portstatus))
+       if (status == 0 && !port_is_suspended(hub, portstatus)) {
+               if (portchange & USB_PORT_STAT_C_SUSPEND)
+                       pm_wakeup_event(&udev->dev, 0);
                goto SuspendCleared;
+       }
 
        /* see 7.1.7.7; affects power usage, but not budgeting */
        if (hub_is_superspeed(hub->hdev))