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    Subject[PATCH 19/26] nova-t-usb2: don't do DMA on stack
    Date
    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@s-opensource.com>
    ---
    drivers/media/usb/dvb-usb/nova-t-usb2.c | 18 +++++++++++++-----
    1 file changed, 13 insertions(+), 5 deletions(-)

    diff --git a/drivers/media/usb/dvb-usb/nova-t-usb2.c b/drivers/media/usb/dvb-usb/nova-t-usb2.c
    index fc7569e2728d..26d7188a1163 100644
    --- a/drivers/media/usb/dvb-usb/nova-t-usb2.c
    +++ b/drivers/media/usb/dvb-usb/nova-t-usb2.c
    @@ -74,22 +74,29 @@ static struct rc_map_table rc_map_haupp_table[] = {
    */
    static int nova_t_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
    {
    - u8 key[5],cmd[2] = { DIBUSB_REQ_POLL_REMOTE, 0x35 }, data,toggle,custom;
    + u8 *buf, data, toggle, custom;
    u16 raw;
    int i;
    struct dibusb_device_state *st = d->priv;

    - dvb_usb_generic_rw(d,cmd,2,key,5,0);
    + buf = kmalloc(5, GFP_KERNEL);
    + if (!buf)
    + return -ENOMEM;
    +
    + buf[0] = DIBUSB_REQ_POLL_REMOTE;
    + buf[1] = 0x35;
    + dvb_usb_generic_rw(d, buf, 2, buf, 5, 0);

    *state = REMOTE_NO_KEY_PRESSED;
    - switch (key[0]) {
    + switch (buf[0]) {
    case DIBUSB_RC_HAUPPAUGE_KEY_PRESSED:
    - raw = ((key[1] << 8) | key[2]) >> 3;
    + raw = ((buf[1] << 8) | buf[2]) >> 3;
    toggle = !!(raw & 0x800);
    data = raw & 0x3f;
    custom = (raw >> 6) & 0x1f;

    - deb_rc("raw key code 0x%02x, 0x%02x, 0x%02x to c: %02x d: %02x toggle: %d\n",key[1],key[2],key[3],custom,data,toggle);
    + deb_rc("raw key code 0x%02x, 0x%02x, 0x%02x to c: %02x d: %02x toggle: %d\n",
    + buf[1], buf[2], buf[3], custom, data, toggle);

    for (i = 0; i < ARRAY_SIZE(rc_map_haupp_table); i++) {
    if (rc5_data(&rc_map_haupp_table[i]) == data &&
    @@ -117,6 +124,7 @@ static int nova_t_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
    break;
    }

    + kfree(buf);
    return 0;
    }

    --
    2.7.4

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