USB: mos7720: fix DMA buffers on stack and clean up send_mos_cmd

Change data-argument type from (void *) to (u8 *) to prevent endianess
problems.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/mos7720.c

@@ -275,13 +275,11 @@ static void mos7720_bulk_out_data_callback(struct urb *urb)
  *	this function will be used for sending command to device
  */
 static int send_mos_cmd(struct usb_serial *serial, __u8 request, __u16 value,
-			__u16 index, void *data)
+			__u16 index, u8 *data)
 {
 	int status;
-	unsigned int pipe;
+	u8 *buf;
 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
-	__u8 requesttype;
-	__u16 size = 0x0000;
 
 	if (value < MOS_MAX_PORT) {
 		if (product == MOSCHIP_DEVICE_ID_7715)
@@ -298,21 +296,23 @@ static int send_mos_cmd(struct usb_serial *serial, __u8 request, __u16 value,
 	}
 
 	if (request == MOS_WRITE) {
-		request = (__u8)MOS_WRITE;
-		requesttype = (__u8)0x40;
-		value  = value + (__u16)*((unsigned char *)data);
-		data = NULL;
-		pipe = usb_sndctrlpipe(serial->dev, 0);
+		value = value + *data;
+		status = usb_control_msg(serial->dev,
+				usb_sndctrlpipe(serial->dev, 0), MOS_WRITE,
+				0x40, value, index, NULL, 0, MOS_WDR_TIMEOUT);
 	} else {
-		request = (__u8)MOS_READ;
-		requesttype = (__u8)0xC0;
-		size = 0x01;
-		pipe = usb_rcvctrlpipe(serial->dev, 0);
-	}
-
-	status = usb_control_msg(serial->dev, pipe, request, requesttype,
-				 value, index, data, size, MOS_WDR_TIMEOUT);
-
+		buf = kmalloc(1, GFP_KERNEL);
+		if (!buf) {
+			status = -ENOMEM;
+			goto out;
+		}
+		status = usb_control_msg(serial->dev,
+				usb_rcvctrlpipe(serial->dev, 0), MOS_READ,
+				0xc0, value, index, buf, 1, MOS_WDR_TIMEOUT);
+		*data = *buf;
+		kfree(buf);
+	}
+out:
 	if (status < 0)
 		dbg("Command Write failed Value %x index %x\n", value, index);