USB: Fix 'bad dma' problem on WDM device disconnect
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>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 47085e5..a97c018 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -281,7 +281,7 @@
desc->sbuf,
desc->validity->transfer_dma);
usb_free_coherent(interface_to_usbdev(desc->intf),
- desc->wMaxCommand,
+ desc->bMaxPacketSize0,
desc->inbuf,
desc->response->transfer_dma);
kfree(desc->orq);