[media] opera1: get rid of on-stack dma buffer

usb_control_msg initiates (and waits for completion of) a dma transfer using
the supplied buffer. That buffer thus has to be seperately allocated on
the heap.

In lib/dma_debug.c the function check_for_stack even warns about it:
	WARNING: at lib/dma-debug.c:866 check_for_stack

Note: This change is tested to compile only, as I don't have the hardware.

Signed-off-by: Florian Mickler <florian@mickler.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/dvb/dvb-usb/opera1.c b/drivers/media/dvb/dvb-usb/opera1.c
index 7e569f4..4258f12 100644 (file)
--- a/drivers/media/dvb/dvb-usb/opera1.c
+++ b/drivers/media/dvb/dvb-usb/opera1.c
@@ -53,27 +53,36 @@ static int opera1_xilinx_rw(struct usb_device *dev, u8 request, u16 value,
                            u8 * data, u16 len, int flags)
 {
        int ret;
-       u8 r;
-       u8 u8buf[len];
-
+       u8 tmp;
+       u8 *buf;
        unsigned int pipe = (flags == OPERA_READ_MSG) ?
                usb_rcvctrlpipe(dev,0) : usb_sndctrlpipe(dev, 0);
        u8 request_type = (flags == OPERA_READ_MSG) ? USB_DIR_IN : USB_DIR_OUT;
 
+       buf = kmalloc(len, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
        if (flags == OPERA_WRITE_MSG)
-               memcpy(u8buf, data, len);
-       ret =
-               usb_control_msg(dev, pipe, request, request_type | USB_TYPE_VENDOR,
-                       value, 0x0, u8buf, len, 2000);
+               memcpy(buf, data, len);
+       ret = usb_control_msg(dev, pipe, request,
+                       request_type | USB_TYPE_VENDOR, value, 0x0,
+                       buf, len, 2000);
 
        if (request == OPERA_TUNER_REQ) {
+               tmp = buf[0];
                if (usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
-                               OPERA_TUNER_REQ, USB_DIR_IN | USB_TYPE_VENDOR,
-                               0x01, 0x0, &r, 1, 2000)<1 || r!=0x08)
-                                       return 0;
+                           OPERA_TUNER_REQ, USB_DIR_IN | USB_TYPE_VENDOR,
+                           0x01, 0x0, buf, 1, 2000) < 1 || buf[0] != 0x08) {
+                       ret = 0;
+                       goto out;
+               }
+               buf[0] = tmp;
        }
        if (flags == OPERA_READ_MSG)
-               memcpy(data, u8buf, len);
+               memcpy(data, buf, len);
+out:
+       kfree(buf);
        return ret;
 }