[PATCH] dmadevices: dma_sync_wait and dma_find_channel undefined

From: Jon Mason
Date: Mon Sep 09 2013 - 19:52:07 EST

dma_sync_wait and dma_find_channel are declared regardless of whether
CONFIG_DMA_ENGINE is enabled, but calling the function without
CONFIG_DMA_ENGINE enabled results "undefined reference" errors.

To get around this, declare dma_sync_wait and dma_find_channel as inline
functions if CONFIG_DMA_ENGINE is undefined.

Signed-off-by: Jon Mason <jon.mason@xxxxxxxxx>
include/linux/dmaengine.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index cb286b1..cd4d1ca 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -958,8 +958,9 @@ dma_set_tx_state(struct dma_tx_state *st, dma_cookie_t last, dma_cookie_t used,

-enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
+struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
+enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
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(const dma_cap_mask_t *mask,
@@ -967,6 +968,14 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name);
void dma_release_channel(struct dma_chan *chan);
+static inline struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
+ return NULL;
+static inline enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
+ return DMA_SUCCESS;
static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
@@ -994,7 +1003,6 @@ static inline void dma_release_channel(struct dma_chan *chan)
int dma_async_device_register(struct dma_device *device);
void dma_async_device_unregister(struct dma_device *device);
void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
-struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
struct dma_chan *net_dma_find_channel(void);
#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
#define dma_request_slave_channel_compat(mask, x, y, dev, name) \

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