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

commit 07e72b95f5038cc82304b9a4a2eb7f9fc391ea68 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index dbc4bf753746f735d86ec443698f70d7503056da..ef8f790d6172fe0b66e8fd963ec059f1b9982406 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2609,7 +2609,7 @@ 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",
@@ -2654,7 +2654,13 @@ 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,