From: Dan Williams <[email protected]> Save someone else the debug cycles of figuring out why a driver's transfer request is failing or causing undefined system behavior. Buffers submitted for dma must come from GFP allocated / DMA-able memory.
Return -EAGAIN matching the return value for dma_mapping_error() cases. Cc: Alan Stern <[email protected]> Cc: Sarah Sharp <[email protected]> Cc: Mathias Nyman <[email protected]> Signed-off-by: Dan Williams <[email protected]> Signed-off-by: Mathias Nyman <[email protected]> --- drivers/usb/core/hcd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 9c4e292..adddc66 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1502,6 +1502,9 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, ret = -EAGAIN; else urb->transfer_flags |= URB_DMA_MAP_PAGE; + } else if (is_vmalloc_addr(urb->transfer_buffer)) { + WARN_ONCE(1, "transfer buffer not dma capable\n"); + ret = -EAGAIN; } else { urb->transfer_dma = dma_map_single( hcd->self.controller, -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
