Commit 877d8425 authored by Vinod Koul's avatar Vinod Koul

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: default avatarkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 9d9f71a8
...@@ -657,6 +657,8 @@ static struct dma_async_tx_descriptor *shdma_prep_slave_sg( ...@@ -657,6 +657,8 @@ static struct dma_async_tx_descriptor *shdma_prep_slave_sg(
direction, flags, false); direction, flags, false);
} }
#define SHDMA_MAX_SG_LEN 32
static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction, size_t period_len, enum dma_transfer_direction direction,
...@@ -668,7 +670,7 @@ static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( ...@@ -668,7 +670,7 @@ static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic(
unsigned int sg_len = buf_len / period_len; unsigned int sg_len = buf_len / period_len;
int slave_id = schan->slave_id; int slave_id = schan->slave_id;
dma_addr_t slave_addr; dma_addr_t slave_addr;
struct scatterlist sgl[sg_len]; struct scatterlist sgl[SHDMA_MAX_SG_LEN];
int i; int i;
if (!chan) if (!chan)
...@@ -676,6 +678,12 @@ static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( ...@@ -676,6 +678,12 @@ static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic(
BUG_ON(!schan->desc_num); 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? */ /* Someone calling slave DMA on a generic channel? */
if (slave_id < 0 || (buf_len < period_len)) { if (slave_id < 0 || (buf_len < period_len)) {
dev_warn(schan->dev, dev_warn(schan->dev,
......
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