USB: hub: handle claim of enabled remote wakeup after reset
authorOliver Neukum <oliver@neukum.org>
Thu, 29 Nov 2012 14:05:57 +0000 (15:05 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 11 Jan 2013 20:15:14 +0000 (12:15 -0800)
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>
drivers/usb/core/hub.c

index 9641e9c..957ed2c 100644 (file)
@@ -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,