patch "USB: Increment wakeup count on remote wakeup." added to usb-linus

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    USB: Increment wakeup count on remote wakeup.

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 83a62c51ba7b3c0bf45150c4eac7aefc6c785e94 Mon Sep 17 00:00:00 2001
From: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Date: Fri, 20 Apr 2018 11:08:21 -0700
Subject: 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>
---
 drivers/usb/core/hcd.c |  1 +
 drivers/usb/core/hub.c | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 777036ae6367..00bb8417050f 100644
--- 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 f6ea16e9f6bb..aa9968d90a48 100644
--- 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))
-- 
2.17.0