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author | Arnd Bergmann <arnd@arndb.de> | 2016-06-13 17:07:33 +0200 |
---|---|---|
committer | Vinod Koul <vinod.koul@intel.com> | 2016-06-13 22:31:42 +0530 |
commit | f67c3bdabbab47555232f1b883d4758792dd2bc4 (patch) | |
tree | 05c6320302e7ee68e611c2cd67aca5fc37214242 /drivers/dma/xilinx | |
parent | e167a0b6dc49cb3694fea888560aa462532951dd (diff) | |
download | linux-stable-f67c3bdabbab47555232f1b883d4758792dd2bc4.tar.gz linux-stable-f67c3bdabbab47555232f1b883d4758792dd2bc4.tar.bz2 linux-stable-f67c3bdabbab47555232f1b883d4758792dd2bc4.zip |
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.c | 6 |
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; |