Merge tag 'ktest-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...

[mirror_ubuntu-bionic-kernel.git] / lib / dma-debug.c

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 8971370bfb1619eb9d3acd332045129542092ee0..60c57ec936dbdcfaf4f0876274fa984ad2c9fd2b 100644 (file)
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1155,6 +1155,11 @@ static void check_unmap(struct dma_debug_entry *ref)
                           dir2name[ref->direction]);
        }
 
+       /*
+        * Drivers should use dma_mapping_error() to check the returned
+        * addresses of dma_map_single() and dma_map_page().
+        * If not, print this warning message. See Documentation/DMA-API.txt.
+        */
        if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
                err_printk(ref->dev, entry,
                           "DMA-API: device driver failed to check map error"