Merge branch 'for-v4.1-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma...

Pull DMA-mapping updates from Marek Szyprowski:
 "This contains two patches, which clarify abiguity in the dma-mapping
  api"

* 'for-v4.1-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  include/dma-mapping: Clarify output of dma_map_sg
  asm/dma-mapping-common: Clarify output of dma_map_sg_attrs

diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index 3378dcf4c31ea85b7206fe8b5e03be828330c56d..940d5ec122c96e5a72173b9db2d0bcff44d39405 100644 (file)
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -39,6 +39,10 @@ static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
        debug_dma_unmap_page(dev, addr, size, dir, true);
 }
 
+/*
+ * dma_maps_sg_attrs returns 0 on error and > 0 on success.
+ * It should never return a value < 0.
+ */
 static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
                                   int nents, enum dma_data_direction dir,
                                   struct dma_attrs *attrs)
@@ -51,6 +55,7 @@ static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
                kmemcheck_mark_initialized(sg_virt(s), s->length);
        BUG_ON(!valid_dma_direction(dir));
        ents = ops->map_sg(dev, sg, nents, dir, attrs);
+       BUG_ON(ents < 0);
        debug_dma_map_sg(dev, sg, nents, ents, dir);
 
        return ents;

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index c3007cb4bfa66fda55b2883f4e08f3fc341176ab..ac07ff090919309c4f51d0a29cfeb9f9a7d673e4 100644 (file)
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -34,6 +34,10 @@ struct dma_map_ops {
        void (*unmap_page)(struct device *dev, dma_addr_t dma_handle,
                           size_t size, enum dma_data_direction dir,
                           struct dma_attrs *attrs);
+       /*
+        * map_sg returns 0 on error and a value > 0 on success.
+        * It should never return a value < 0.
+        */
        int (*map_sg)(struct device *dev, struct scatterlist *sg,
                      int nents, enum dma_data_direction dir,
                      struct dma_attrs *attrs);