[PATCH 1/1][F/G/H] USB: Verify the port status when timeout happens during port suspend

[chris.chiu at canonical.com]

From: Chris Chiu <chris.chiu at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/1928242

On the Realtek high-speed Hub(0bda:5487), the port which has wakeup
enabled_descendants will sometimes timeout when setting PORT_SUSPEND
feature. After checking the PORT_SUSPEND bit in wPortStatus, it is
already set which means the port has been suspended. We should treat
it suspended to make sure it will be resumed correctly.

Acked-by: Alan Stern <stern at rowland.harvard.edu>
Signed-off-by: Chris Chiu <chris.chiu at canonical.com>
Link: https://lore.kernel.org/r/20210514045405.5261-2-chris.chiu@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit 7142452387c72207f34683382b04f38499da58f7 linux-next)
Signed-off-by: Chris Chiu <chris.chiu at canonical.com>
---
 drivers/usb/core/hub.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b1e14beaac5f..75e214b6af46 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3318,6 +3318,26 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 		status = 0;
 	}
 	if (status) {
+		/* Check if the port has been suspended for the timeout case
+		 * to prevent the suspended port from incorrect handling.
+		 */
+		if (status == -ETIMEDOUT) {
+			int ret;
+			u16 portstatus, portchange;
+
+			portstatus = portchange = 0;
+			ret = hub_port_status(hub, port1, &portstatus,
+					&portchange);
+
+			dev_dbg(&port_dev->dev,
+				"suspend timeout, status %04x\n", portstatus);
+
+			if (ret == 0 && port_is_suspended(hub, portstatus)) {
+				status = 0;
+				goto suspend_done;
+			}
+		}
+
 		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
 
 		/* Try to enable USB3 LTM again */
@@ -3334,6 +3354,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 		if (!PMSG_IS_AUTO(msg))
 			status = 0;
 	} else {
+ suspend_done:
 		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
 				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
 				udev->do_remote_wakeup);
-- 
2.20.1