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.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
29d2fef8be