[PATCH] dma: Make the 'mask' parameter of __dma_request_channel const

From: Lars-Peter Clausen
Date: Mon Mar 25 2013 - 08:21:52 EST


The 'mask' parameter is not modified in __dma_request_channel and really
shouldn't be. Make this explicit by making the parameter const.

Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/dma/dmaengine.c | 9 ++++++---
include/linux/dmaengine.h | 11 ++++++-----
2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index b2728d6..d07ef7d 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -174,7 +174,8 @@ static struct class dma_devclass = {
#define dma_device_satisfies_mask(device, mask) \
__dma_device_satisfies_mask((device), &(mask))
static int
-__dma_device_satisfies_mask(struct dma_device *device, dma_cap_mask_t *want)
+__dma_device_satisfies_mask(struct dma_device *device,
+ const dma_cap_mask_t *want)
{
dma_cap_mask_t has;

@@ -463,7 +464,8 @@ static void dma_channel_rebalance(void)
}
}

-static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev,
+static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
+ struct dma_device *dev,
dma_filter_fn fn, void *fn_param)
{
struct dma_chan *chan;
@@ -505,7 +507,8 @@ static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_devic
* @fn: optional callback to disposition available channels
* @fn_param: opaque parameter to pass to dma_filter_fn
*/
-struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param)
+struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
+ dma_filter_fn fn, void *fn_param)
{
struct dma_device *device, *_d;
struct dma_chan *chan = NULL;
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 91ac8da..2511742 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -967,8 +967,9 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
#ifdef CONFIG_DMA_ENGINE
enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
void dma_issue_pending_all(void);
-struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
struct dma_chan *dma_request_slave_channel(struct device *dev, char *name);
+struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
+ dma_filter_fn fn, void *fn_param);
void dma_release_channel(struct dma_chan *chan);
#else
static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
@@ -978,7 +979,7 @@ static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descript
static inline void dma_issue_pending_all(void)
{
}
-static inline struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask,
+static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
dma_filter_fn fn, void *fn_param)
{
return NULL;
@@ -1005,9 +1006,9 @@ struct dma_chan *net_dma_find_channel(void);
__dma_request_slave_channel_compat(&(mask), x, y, dev, name)

static inline struct dma_chan
-*__dma_request_slave_channel_compat(dma_cap_mask_t *mask, dma_filter_fn fn,
- void *fn_param, struct device *dev,
- char *name)
+*__dma_request_slave_channel_compat(const dma_cap_mask_t *mask,
+ dma_filter_fn fn, void *fn_param,
+ struct device *dev, char *name)
{
struct dma_chan *chan;

--
1.8.0

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