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dmaengine: sh: don't use dynamic static allocation

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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>
This commit is contained in:
Vinod Koul 2014-06-02 09:40:00 +05:30
parent 9d9f71a804
commit 877d842507
1 changed files with 9 additions and 1 deletions
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10
drivers/dma/sh/shdma-base.c
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@ -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,