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authorArnd Bergmann <arnd@arndb.de>2016-06-13 18:07:33 +0300
committerVinod Koul <vinod.koul@intel.com>2016-06-13 20:01:42 +0300
commitf67c3bdabbab47555232f1b883d4758792dd2bc4 (patch)
tree05c6320302e7ee68e611c2cd67aca5fc37214242 /drivers/dma/xilinx
parente167a0b6dc49cb3694fea888560aa462532951dd (diff)
downloadlinux-f67c3bdabbab47555232f1b883d4758792dd2bc4.tar.xz
dmaengine: xilinx-vdma: add some sanity checks
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. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/xilinx')
-rw-r--r--drivers/dma/xilinx/xilinx_vdma.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 0af0cf4b5f2e..914268bc9990 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -1745,8 +1745,14 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
int i;
u32 reg;
+ if (!period_len)
+ return NULL;
+
num_periods = buf_len / period_len;
+ if (!num_periods)
+ return NULL;
+
if (!is_slave_direction(direction))
return NULL;