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    Subject[21/27] USB: Fix bad dma problem on WDM device disconnect
    2.6.32-longterm review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Robert Lukassen <Robert.Lukassen@tomtom.com>

    commit 878b753e32ca765cd346a5d3038d630178ec78ff upstream.
    [ changed s/usb_free_coherent/usb_buffer_free/ for 2.6.32.x]

    In the WDM class driver a disconnect event leads to calls to
    usb_free_coherent to put back two USB DMA buffers allocated earlier.
    The call to usb_free_coherent uses a different size parameter
    (desc->wMaxCommand) than the corresponding call to usb_alloc_coherent
    (desc->bMaxPacketSize0).

    When a disconnect event occurs, this leads to 'bad dma' complaints
    from usb core because the USB DMA buffer is being pushed back to the
    'buffer-2048' pool from which it has not been allocated.

    This patch against the most recent linux-2.6 kernel ensures that the
    parameters used by usb_alloc_coherent & usb_free_coherent calls in
    cdc-wdm.c match.

    Signed-off-by: Robert Lukassen <robert.lukassen@tomtom.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
    Signed-off-by: Bjørn Mork <bjorn@mork.no>

    ---
    drivers/usb/class/cdc-wdm.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/drivers/usb/class/cdc-wdm.c
    +++ b/drivers/usb/class/cdc-wdm.c
    @@ -277,7 +277,7 @@ static void cleanup(struct wdm_device *d
    desc->sbuf,
    desc->validity->transfer_dma);
    usb_buffer_free(interface_to_usbdev(desc->intf),
    - desc->wMaxCommand,
    + desc->bMaxPacketSize0,
    desc->inbuf,
    desc->response->transfer_dma);
    kfree(desc->orq);

    --
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