rtlwifi: rtl8192cu: Fix kernel deadlock

commit 414b7e3b upstream.

The USB mini-driver in rtlwifi, which is used by rtl8192cu, issues a call to
usb_control_msg() with a timeout value of 0. In some instances where the
interface is shutting down, this infinite wait results in a CPU deadlock. A
one second timeout fixes this problem without affecting any normal operations.

This bug is reported at https://bugzilla.novell.com/show_bug.cgi?id=927786.
Reported-by: Bernhard Wiedemann <bwiedemann@suse.com>
Tested-by: Bernhard Wiedemann <bwiedemann@suse.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Bernhard Wiedemann <bwiedemann@suse.com>
Cc: Takashi Iwai<tiwai@suse.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/wireless/rtlwifi/usb.c

@@ -126,7 +126,7 @@ static int _usbctrl_vendorreq_sync_read(struct usb_device *udev, u8 request,
 
 	do {
 		status = usb_control_msg(udev, pipe, request, reqtype, value,
-					 index, pdata, len, 0); /*max. timeout*/
+					 index, pdata, len, 1000);
 		if (status < 0) {
 			/* firmware download is checksumed, don't retry */
 			if ((value >= FW_8192C_START_ADDRESS &&