[ARM] 3942/1: ARM: comment: consistent_sync should not be called directly

/*
 * Note: Drivers should NOT use this function directly, as it will break
 * platforms with CONFIG_DMABOUNCE.
 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
 */

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 7 insertions, 0 deletions

diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c
index 50e6b6bfb2e2..b797217e82be 100644
--- a/arch/arm/mm/consistent.c
+++ b/arch/arm/mm/consistent.c
@@ -476,6 +476,9 @@ core_initcall(consistent_init);
 
 /*
  * Make an area consistent for devices.
+ * Note: Drivers should NOT use this function directly, as it will break
+ * platforms with CONFIG_DMABOUNCE.
+ * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
  */
 void consistent_sync(void *vaddr, size_t size, int direction)
 {
diff --git a/include/asm-arm/dma-mapping.h b/include/asm-arm/dma-mapping.h
index 55eb4dc3253d..666617711c81 100644
--- a/include/asm-arm/dma-mapping.h
+++ b/include/asm-arm/dma-mapping.h
@@ -12,6 +12,10 @@
  * uncached, unwrite-buffered mapped memory space for use with DMA
  * devices.  This is the "generic" version.  The PCI specific version
  * is in pci.h
+ *
+ * Note: Drivers should NOT use this function directly, as it will break
+ * platforms with CONFIG_DMABOUNCE.
+ * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
  */
 extern void consistent_sync(void *kaddr, size_t size, int rw);