[PATCH] arm: add comment about dma_supported()

)


From: Russell King <[e-mail]>

The ARM dma_supported() is rather basic, and I don't think it takes into
account everything that it should do (eg, whether the mask agrees with what
we'd return for GFP_DMA allocations). Note this.

Signed-off-by: Russell King <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/asm-arm/dma-mapping.h

···
  * properly.  For example, if your device can only drive the low 24-bits
  * during bus mastering, then you would pass 0x00ffffff as the mask
  * to this function.
+ *
+ * FIXME: This should really be a platform specific issue - we should
+ * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
  */
 static inline int dma_supported(struct device *dev, u64 mask)
 {