USB: hub: handle claim of enabled remote wakeup after reset

Some touchscreens have buggy firmware which claims
remote wakeup to be enabled after a reset. They nevertheless
crash if the feature is cleared by the host.
Add a check for reset resume before checking for
an enabled remote wakeup feature. On compliant
devices the feature must be cleared after a reset anyway.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
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/hub.c b/drivers/usb/core/hub.c
index 9641e9c1dec591994cb0c81c2dcb931f38f04a75..957ed2c41482706a4b9d1441815173e4deea2200 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3000,7 +3000,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 static int finish_port_resume(struct usb_device *udev)
 {
        int     status = 0;
-       u16     devstatus;
+       u16     devstatus = 0;
 
        /* caller owns the udev device lock */
        dev_dbg(&udev->dev, "%s\n",
@@ -3045,7 +3045,13 @@ static int finish_port_resume(struct usb_device *udev)
        if (status) {
                dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
                                status);
-       } else if (udev->actconfig) {
+       /*
+        * There are a few quirky devices which violate the standard
+        * by claiming to have remote wakeup enabled after a reset,
+        * which crash if the feature is cleared, hence check for
+        * udev->reset_resume
+        */
+       } else if (udev->actconfig && !udev->reset_resume) {
                le16_to_cpus(&devstatus);
                if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
                        status = usb_control_msg(udev,