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| author | Vinod Koul <vinod.koul@intel.com> | 2014-06-02 06:10:00 +0200 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2014-06-03 08:05:33 +0200 |
| commit | 877d8425072b50965f6f04ea3a127928f66db72f (patch) | |
| tree | 386a87da4c6631e4b25bab821a31ed370fe114f0 /drivers/dma/sh | |
| parent | dmaengine: sh: fix print specifier warnings (diff) | |
| download | linux-877d8425072b50965f6f04ea3a127928f66db72f.tar.xz linux-877d8425072b50965f6f04ea3a127928f66db72f.zip | |
dmaengine: sh: don't use dynamic static allocation
dynamic stack allocation in kernel is considered bad as kernel stack is low and
we get warns on few archs as reported by kbuild test robot
>> drivers/dma/sh/shdma-base.c:671:32: sparse: Variable length array is used.
>> drivers/dma/sh/shdma-base.c:701:1: warning: 'shdma_prep_dma_cyclic' uses
>> dynamic stack allocation [enabled by default]
Fix this by making a static array of 32 which should be sufficient for
shdma_prep_dma_cyclic which only user in kernel is audio and 32 periods for
audio seems quite sufficient atm
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/sh')
| -rw-r--r-- | drivers/dma/sh/shdma-base.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 591b9d8cfd7f..b35007e21e6b 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -657,6 +657,8 @@ static struct dma_async_tx_descriptor *shdma_prep_slave_sg( direction, flags, false); } +#define SHDMA_MAX_SG_LEN 32 + static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, size_t period_len, enum dma_transfer_direction direction, @@ -668,7 +670,7 @@ static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( unsigned int sg_len = buf_len / period_len; int slave_id = schan->slave_id; dma_addr_t slave_addr; - struct scatterlist sgl[sg_len]; + struct scatterlist sgl[SHDMA_MAX_SG_LEN]; int i; if (!chan) @@ -676,6 +678,12 @@ static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( BUG_ON(!schan->desc_num); + if (sg_len > SHDMA_MAX_SG_LEN) { + dev_err(schan->dev, "sg length %d exceds limit %d", + sg_len, SHDMA_MAX_SG_LEN); + return NULL; + } + /* Someone calling slave DMA on a generic channel? */ if (slave_id < 0 || (buf_len < period_len)) { dev_warn(schan->dev, |