rt2800usb:fix hang during firmware load

The device 057c:8501 (AVM Fritz! WLAN v2 rev. B) boots into a state that does
not actually require loading a firmware file. The vendors driver finds out
about this by checking a firmware state register, so this patch adds this here.

Finally, with this patch applied, my wifi dongle actually becomes
useful (scan + connect to wpa network works).
Signed-off-by: Michael Braun <michael-dev@fami-braun.de>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800usb.c

@@ -278,8 +278,13 @@ static int rt2800usb_write_firmware(struct rt2x00_dev *rt2x00dev,
 	/*
 	 * Write firmware to device.
 	 */
-	rt2x00usb_register_multiwrite(rt2x00dev, FIRMWARE_IMAGE_BASE,
-				      data + offset, length);
+	if (rt2800usb_autorun_detect(rt2x00dev)) {
+		rt2x00_info(rt2x00dev,
+			    "Firmware loading not required - NIC in AutoRun mode\n");
+	} else {
+		rt2x00usb_register_multiwrite(rt2x00dev, FIRMWARE_IMAGE_BASE,
+					      data + offset, length);
+	}
 
 	rt2x00usb_register_write(rt2x00dev, H2M_MAILBOX_CID, ~0);
 	rt2x00usb_register_write(rt2x00dev, H2M_MAILBOX_STATUS, ~0);