USB: opticon: fix DMA from stack

commit ea0dbebffe118724cd4df7d9b071ea8ee48d48f0 upstream.

Make sure to allocate the control-message buffer dynamically as some
platforms cannot do DMA from stack.

Note that only the first byte of the old buffer was used.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index c248a91..5b83e10 100644 (file)
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -160,7 +160,11 @@ static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 {
        struct usb_serial *serial = port->serial;
        int retval;
-       u8 buffer[2];
+       u8 *buffer;
+
+       buffer = kzalloc(1, GFP_KERNEL);
+       if (!buffer)
+               return -ENOMEM;
 
        buffer[0] = val;
        /* Send the message to the vendor control endpoint
@@ -169,6 +173,7 @@ static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
                                requesttype,
                                USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                                0, 0, buffer, 1, 0);
+       kfree(buffer);
 
        return retval;
 }