USB: Verify the port status when timeout happens during port suspend

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@rowland.harvard.edu>
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
Link: https://lore.kernel.org/r/20210514045405.5261-2-chris.chiu@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index fc7d6cd..bbe7c17 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3385,6 +3385,26 @@ 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 */
@@ -3401,6 +3421,7 @@ 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);