USB: ftdi_sio: fix latency-timeout endianess bug

Also fixes DMA transfer to stack for latency buffer.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index ec901ed5d93c..59b6cbf020a0 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1181,22 +1181,28 @@ static int read_latency_timer(struct usb_serial_port *port)
 {
         struct ftdi_private *priv = usb_get_serial_port_data(port);
         struct usb_device *udev = port->serial->dev;
-        unsigned short latency = 0;
+        unsigned char *buf;
         int rv = 0;
 
         dbg("%s", __func__);
 
+        buf = kmalloc(1, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
         rv = usb_control_msg(udev,
                              usb_rcvctrlpipe(udev, 0),
                              FTDI_SIO_GET_LATENCY_TIMER_REQUEST,
                              FTDI_SIO_GET_LATENCY_TIMER_REQUEST_TYPE,
                              0, priv->interface,
-                             (char *) &latency, 1, WDR_TIMEOUT);
-
+                             buf, 1, WDR_TIMEOUT);
         if (rv < 0)
                 dev_err(&port->dev, "Unable to read latency timer: %i\n", rv);
         else
-                priv->latency = latency;
+                priv->latency = buf[0];
+
+        kfree(buf);
+
         return rv;
 }