[media] s2255drv: don't use stack for DMA

The USB control messages require DMA to work. We cannot pass
a stack-allocated buffer, as it is not warranted that the
stack would be into a DMA enabled area.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c
index c3a0e87066ebbbd78cda420a48f7dc76ab511107..f7bb78c1873c915d9db9574ea024cc77a355c413 100644 (file)
--- a/drivers/media/usb/s2255/s2255drv.c
+++ b/drivers/media/usb/s2255/s2255drv.c
@@ -1901,19 +1901,30 @@ static long s2255_vendor_req(struct s2255_dev *dev, unsigned char Request,
                             s32 TransferBufferLength, int bOut)
 {
        int r;
+       unsigned char *buf;
+
+       buf = kmalloc(TransferBufferLength, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
        if (!bOut) {
                r = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
                                    Request,
                                    USB_TYPE_VENDOR | USB_RECIP_DEVICE |
                                    USB_DIR_IN,
-                                   Value, Index, TransferBuffer,
+                                   Value, Index, buf,
                                    TransferBufferLength, HZ * 5);
+
+               if (r >= 0)
+                       memcpy(TransferBuffer, buf, TransferBufferLength);
        } else {
+               memcpy(buf, TransferBuffer, TransferBufferLength);
                r = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
                                    Request, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-                                   Value, Index, TransferBuffer,
+                                   Value, Index, buf,
                                    TransferBufferLength, HZ * 5);
        }
+       kfree(buf);
        return r;
 }