[PATCH] dma: xilinx-vdma: add some sanity checks

[Vinod Koul]

On Mon, Jun 13, 2016 at 05:07:33PM +0200, Arnd Bergmann wrote:
> The newly added xilinx_dma_prep_dma_cyclic function sometimes causes
> a gcc warning about the use of the segment function in case
> we never run into the inner loop of the function:
> 
> dma/xilinx/xilinx_vdma.c: In function 'xilinx_dma_prep_dma_cyclic':
> dma/xilinx/xilinx_vdma.c:1808:23: error: 'segment' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>    segment->hw.control |= XILINX_DMA_BD_SOP;
> 
> This can only happen if the period len is zero (which would cause other
> problems earlier), or if the buffer is shorter than a period. Neither
> of them should ever happen, but by adding an explicit check for these two
> cases, we can abort in a more controlled way, and the compiler is
> able to see that we never use uninitialized data.

Applied after fixing subsystem name

Thanks
-- 
~Vinod