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>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 9641e9c1dec5..957ed2c41482 100644
--- 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,