[21/27] USB: Fix bad dma problem on WDM device disconnect
From: Greg KH <gregkh@suse.de>
Date: 2012-01-23 23:46:12
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2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Robert Lukassen <redacted> 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 <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Bj��rn 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);