Blackfin: dma-mapping: fix thinko in constant optimization

Make sure the non-constant version of the dma_sync functions actually
complete instead of recursively calling itself forever.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/include/asm/dma-mapping.h

@@ -44,13 +44,8 @@ dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 extern void
 __dma_sync(dma_addr_t addr, size_t size, enum dma_data_direction dir);
 static inline void
-_dma_sync(dma_addr_t addr, size_t size, enum dma_data_direction dir)
+__dma_sync_inline(dma_addr_t addr, size_t size, enum dma_data_direction dir)
 {
-	if (!__builtin_constant_p(dir)) {
-		__dma_sync(addr, size, dir);
-		return;
-	}
-
 	switch (dir) {
 	case DMA_NONE:
 		BUG();
@@ -64,6 +59,14 @@ _dma_sync(dma_addr_t addr, size_t size, enum dma_data_direction dir)
 		break;
 	}
 }
+static inline void
+_dma_sync(dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+	if (__builtin_constant_p(dir))
+		__dma_sync_inline(addr, size, dir);
+	else
+		__dma_sync(addr, size, dir);
+}
 
 /*
  * Map a single buffer of the indicated size for DMA in streaming mode.

arch/blackfin/kernel/dma-mapping.c

@@ -116,7 +116,7 @@ EXPORT_SYMBOL(dma_free_coherent);
 void __dma_sync(dma_addr_t addr, size_t size,
 		enum dma_data_direction dir)
 {
-	_dma_sync(addr, size, dir);
+	__dma_sync_inline(addr, size, dir);
 }
 EXPORT_SYMBOL(__dma_sync);